Changes since the initial port

The following section lists changes to this file in mathlib3 and mathlib4 that occured after the initial port. Most recent changes are shown first. Hovering over a commit will show all commits associated with the same mathlib3 commit.

Changes in mathlib3

48fb5b52

(last sync)

refactor(*): move all mk_simp_attribute commands to 1 file (#19223)

Diff

@@ -100,9 +100,6 @@ end
 We define it here so it is a shared import.
 -/
 
-mk_simp_attribute ghost_simps
-"Simplification rules for ghost equations"
-
 namespace tactic
 namespace interactive
 setup_tactic_parser

168ad7fc

(first ported)

Changes in mathlib3port

mathlib3

mathlib3port

48fb5b52

bump to nightly-2024-04-07-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

b03b8656

Diff

@@ -5,7 +5,7 @@ Authors: Johan Commelin, Robert Y. Lewis
 -/
 import Algebra.Ring.ULift
 import RingTheory.WittVector.Basic
-import Data.MvPolynomial.Funext
+import Algebra.MvPolynomial.Funext
 
 #align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"

48fb5b52

bump to nightly-2024-04-06-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

e34029c9

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2020 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 -/
-import Algebra.Ring.Ulift
+import Algebra.Ring.ULift
 import RingTheory.WittVector.Basic
 import Data.MvPolynomial.Funext

48fb5b52

bump to nightly-2024-03-17-08

mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83

22f01ce4

Diff

@@ -186,7 +186,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq' (f g : ℕ → MvPolynomial (idx × 
   by
   ext1 n
   apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
-  rw [← Function.funext_iff] at h 
+  rw [← Function.funext_iff] at h
   replace h :=
     congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
@@ -200,7 +200,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq (f g : ℕ → MvPolynomial ℕ ℤ)
   by
   ext1 n
   apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
-  rw [← Function.funext_iff] at h 
+  rw [← Function.funext_iff] at h
   replace h :=
     congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
@@ -266,7 +266,7 @@ theorem ext {f g} (hf : IsPoly p f) (hg : IsPoly p g)
   intro x
   simp only [hom_bind₁]
   specialize h (ULift ℤ) (mk p fun i => ⟨x i⟩) k
-  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h 
+  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h
   apply (ulift.ring_equiv.symm : ℤ ≃+* _).Injective
   simp only [← RingEquiv.coe_toRingHom, map_eval₂_hom]
   convert h using 1
@@ -628,7 +628,7 @@ theorem ext {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
   intro x
   simp only [hom_bind₁]
   specialize h (ULift ℤ) (mk p fun i => ⟨x (0, i)⟩) (mk p fun i => ⟨x (1, i)⟩) k
-  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h 
+  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h
   apply (ulift.ring_equiv.symm : ℤ ≃+* _).Injective
   simp only [← RingEquiv.coe_toRingHom, map_eval₂_hom]
   convert h using 1

48fb5b52

bump to nightly-2023-09-24-06

mathlib commit https://github.com/leanprover-community/mathlib/commit/ce64cd319bb6b3e82f31c2d38e79080d377be451

5655435f

Diff

@@ -3,9 +3,9 @@ Copyright (c) 2020 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 -/
-import Mathbin.Algebra.Ring.Ulift
-import Mathbin.RingTheory.WittVector.Basic
-import Mathbin.Data.MvPolynomial.Funext
+import Algebra.Ring.Ulift
+import RingTheory.WittVector.Basic
+import Data.MvPolynomial.Funext
 
 #align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"

48fb5b52

bump to nightly-2023-07-20-09

mathlib commit https://github.com/leanprover-community/mathlib/commit/8ea5598db6caeddde6cb734aa179cc2408dbd345

9c56d0dd

Diff

@@ -2,16 +2,13 @@
 Copyright (c) 2020 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
-
-! This file was ported from Lean 3 source module ring_theory.witt_vector.is_poly
-! leanprover-community/mathlib commit 48fb5b5280e7c81672afc9524185ae994553ebf4
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Algebra.Ring.Ulift
 import Mathbin.RingTheory.WittVector.Basic
 import Mathbin.Data.MvPolynomial.Funext
 
+#align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
+
 /-!
 # The `is_poly` predicate

48fb5b52

bump to nightly-2023-07-04-01

mathlib commit https://github.com/leanprover-community/mathlib/commit/728ef9dbb281241906f25cbeb30f90d83e0bb451

05318d71

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 
 ! This file was ported from Lean 3 source module ring_theory.witt_vector.is_poly
-! leanprover-community/mathlib commit 6b31d1eebd64eab86d5bd9936bfaada6ca8b5842
+! leanprover-community/mathlib commit 48fb5b5280e7c81672afc9524185ae994553ebf4
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -98,10 +98,12 @@ end
 -/
 
 
--- PLEASE REPORT THIS TO MATHPORT DEVS, THIS SHOULD NOT HAPPEN.
--- failed to format: unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
-/-- Simplification rules for ghost equations -/ register_simp_attr ghost_simps
+/-
+### Simplification tactics
 
+`ghost_simp` is used later in the development for certain simplifications.
+We define it here so it is a shared import.
+-/
 namespace Tactic
 
 namespace Interactive

6b31d1ee

bump to nightly-2023-06-28-19

mathlib commit https://github.com/leanprover-community/mathlib/commit/8b981918a93bc45a8600de608cde7944a80d92b9

6577c9bd

Diff

@@ -530,7 +530,7 @@ def onePoly (n : ℕ) : MvPolynomial ℕ ℤ :=
 @[simp]
 theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomial p ℤ n) = 1 :=
   by
-  rw [wittPolynomial_eq_sum_c_mul_x_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
+  rw [wittPolynomial_eq_sum_C_mul_X_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
   ·
     simp only [one_poly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]

6b31d1ee

bump to nightly-2023-06-13-21

mathlib commit https://github.com/leanprover-community/mathlib/commit/9fb8964792b4237dac6200193a0d533f1b3f7423

829520ac

Diff

@@ -165,7 +165,6 @@ universe u
 
 variable {p : ℕ} {R S : Type u} {σ idx : Type _} [hp : Fact p.Prime] [CommRing R] [CommRing S]
 
--- mathport name: expr𝕎
 local notation "𝕎" => WittVector p
 
 -- type as `\bbW`
@@ -173,8 +172,6 @@ open MvPolynomial
 
 open Function (uncurry)
 
-include hp
-
 variable (p)
 
 noncomputable section
@@ -184,6 +181,7 @@ noncomputable section
 -/
 
 
+#print WittVector.poly_eq_of_wittPolynomial_bind_eq' /-
 theorem poly_eq_of_wittPolynomial_bind_eq' (f g : ℕ → MvPolynomial (idx × ℕ) ℤ)
     (h : ∀ n, bind₁ f (wittPolynomial p _ n) = bind₁ g (wittPolynomial p _ n)) : f = g :=
   by
@@ -195,7 +193,9 @@ theorem poly_eq_of_wittPolynomial_bind_eq' (f g : ℕ → MvPolynomial (idx × 
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
     bind₁_wittPolynomial_xInTermsOfW, bind₁_X_right] using h
 #align witt_vector.poly_eq_of_witt_polynomial_bind_eq' WittVector.poly_eq_of_wittPolynomial_bind_eq'
+-/
 
+#print WittVector.poly_eq_of_wittPolynomial_bind_eq /-
 theorem poly_eq_of_wittPolynomial_bind_eq (f g : ℕ → MvPolynomial ℕ ℤ)
     (h : ∀ n, bind₁ f (wittPolynomial p _ n) = bind₁ g (wittPolynomial p _ n)) : f = g :=
   by
@@ -207,8 +207,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq (f g : ℕ → MvPolynomial ℕ ℤ)
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
     bind₁_wittPolynomial_xInTermsOfW, bind₁_X_right] using h
 #align witt_vector.poly_eq_of_witt_polynomial_bind_eq WittVector.poly_eq_of_wittPolynomial_bind_eq
-
-omit hp
+-/
 
 #print WittVector.IsPoly /-
 -- Ideally, we would generalise this to n-ary functions
@@ -251,8 +250,7 @@ instance : Inhabited (IsPoly p fun _ _ => id) :=
 
 variable {p}
 
-include hp
-
+#print WittVector.IsPoly.ext /-
 theorem ext {f g} (hf : IsPoly p f) (hg : IsPoly p g)
     (h :
       ∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R) (n : ℕ),
@@ -281,8 +279,7 @@ theorem ext {f g} (hf : IsPoly p f) (hg : IsPoly p g)
     apply eval₂_hom_congr (RingHom.ext_int _ _) _ rfl
     simp only [coeff_mk]; rfl
 #align witt_vector.is_poly.ext WittVector.IsPoly.ext
-
-omit hp
+-/
 
 #print WittVector.IsPoly.comp /-
 /-- The composition of polynomial functions is polynomial. -/
@@ -482,8 +479,6 @@ unsafe def is_poly_attr : user_attribute
 
 end Tactic
 
-include hp
-
 /-!
 ### `is_poly` instances
 
@@ -516,21 +511,22 @@ instance zeroIsPoly : IsPoly p fun _ _ _ => 0 :=
 #align witt_vector.zero_is_poly WittVector.zeroIsPoly
 -/
 
+#print WittVector.bind₁_zero_wittPolynomial /-
 @[simp]
 theorem bind₁_zero_wittPolynomial (n : ℕ) :
     bind₁ (0 : ℕ → MvPolynomial ℕ R) (wittPolynomial p R n) = 0 := by
   rw [← aeval_eq_bind₁, aeval_zero, constantCoeff_wittPolynomial, RingHom.map_zero]
 #align witt_vector.bind₁_zero_witt_polynomial WittVector.bind₁_zero_wittPolynomial
+-/
 
-omit hp
-
+#print WittVector.onePoly /-
 /-- The coefficients of `1 : 𝕎 R` as polynomials. -/
 def onePoly (n : ℕ) : MvPolynomial ℕ ℤ :=
   if n = 0 then 1 else 0
 #align witt_vector.one_poly WittVector.onePoly
+-/
 
-include hp
-
+#print WittVector.bind₁_onePoly_wittPolynomial /-
 @[simp]
 theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomial p ℤ n) = 1 :=
   by
@@ -543,6 +539,7 @@ theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomi
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]; decide
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
+-/
 
 #print WittVector.oneIsPoly /-
 /-- The function that is constantly one on Witt vectors is a polynomial function. -/
@@ -558,8 +555,6 @@ instance oneIsPoly : IsPoly p fun _ _ _ => 1 :=
 
 end ZeroOne
 
-omit hp
-
 #print WittVector.addIsPoly₂ /-
 /-- Addition of Witt vectors is a polynomial function. -/
 @[is_poly]
@@ -576,8 +571,7 @@ theorem mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
 #align witt_vector.mul_is_poly₂ WittVector.mulIsPoly₂
 -/
 
-include hp
-
+#print WittVector.IsPoly.map /-
 -- unfortunately this is not universe polymorphic, merely because `f` isn't
 theorem IsPoly.map {f} (hf : IsPoly p f) (g : R →+* S) (x : 𝕎 R) : map g (f x) = f (map g x) :=
   by
@@ -590,11 +584,10 @@ theorem IsPoly.map {f} (hf : IsPoly p f) (g : R →+* S) (x : 𝕎 R) : map g (f
   apply eval₂_hom_congr (RingHom.ext_int _ _) _ rfl
   simp only [map_coeff]
 #align witt_vector.is_poly.map WittVector.IsPoly.map
+-/
 
 namespace IsPoly₂
 
-omit hp
-
 instance [Fact p.Prime] : Inhabited (IsPoly₂ p _) :=
   ⟨addIsPoly₂⟩
 
@@ -618,8 +611,7 @@ theorem compRight {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
 #align witt_vector.is_poly₂.comp_right WittVector.IsPoly₂.compRight
 -/
 
-include hp
-
+#print WittVector.IsPoly₂.ext /-
 theorem ext {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
     (h :
       ∀ (R : Type u) [_Rcr : CommRing R] (x y : 𝕎 R) (n : ℕ),
@@ -650,7 +642,9 @@ theorem ext {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
     ext ⟨b, _⟩
     fin_cases b <;> simp only [coeff_mk, uncurry] <;> rfl
 #align witt_vector.is_poly₂.ext WittVector.IsPoly₂.ext
+-/
 
+#print WittVector.IsPoly₂.map /-
 -- unfortunately this is not universe polymorphic, merely because `f` isn't
 theorem map {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎 R) :
     map g (f x y) = f (map g x) (map g y) :=
@@ -664,6 +658,7 @@ theorem map {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎 R) :
   try ext ⟨i, k⟩; fin_cases i
   all_goals simp only [map_coeff, Matrix.cons_val_zero, Matrix.head_cons, Matrix.cons_val_one]
 #align witt_vector.is_poly₂.map WittVector.IsPoly₂.map
+-/
 
 end IsPoly₂

6b31d1ee

bump to nightly-2023-06-10-03

mathlib commit https://github.com/leanprover-community/mathlib/commit/a3e83f0fa4391c8740f7d773a7a9b74e311ae2a3

e13a28eb

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 
 ! This file was ported from Lean 3 source module ring_theory.witt_vector.is_poly
-! leanprover-community/mathlib commit 168ad7fc5d8173ad38be9767a22d50b8ecf1cd00
+! leanprover-community/mathlib commit 6b31d1eebd64eab86d5bd9936bfaada6ca8b5842
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -15,6 +15,9 @@ import Mathbin.Data.MvPolynomial.Funext
 /-!
 # The `is_poly` predicate
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 `witt_vector.is_poly` is a (type-valued) predicate on functions `f : Π R, 𝕎 R → 𝕎 R`.
 It asserts that there is a family of polynomials `φ : ℕ → mv_polynomial ℕ ℤ`,
 such that the `n`th coefficient of `f x` is equal to `φ n` evaluated on the coefficients of `x`.

168ad7fc

bump to nightly-2023-06-08-23

mathlib commit https://github.com/leanprover-community/mathlib/commit/31c24aa72e7b3e5ed97a8412470e904f82b81004

d3cfe2e3

Diff

@@ -95,11 +95,8 @@ end
 -/
 
 
-/- failed to parenthesize: unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
-[PrettyPrinter.parenthesize.input] (Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr
-     [(Command.docComment "/--" "Simplification rules for ghost equations -/")]
-     "register_simp_attr"
-     `ghost_simps)-/-- failed to format: unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
+-- PLEASE REPORT THIS TO MATHPORT DEVS, THIS SHOULD NOT HAPPEN.
+-- failed to format: unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
 /-- Simplification rules for ghost equations -/ register_simp_attr ghost_simps
 
 namespace Tactic
@@ -210,6 +207,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq (f g : ℕ → MvPolynomial ℕ ℤ)
 
 omit hp
 
+#print WittVector.IsPoly /-
 -- Ideally, we would generalise this to n-ary functions
 -- But we don't have a good theory of n-ary compositions in mathlib
 /-- A function `f : Π R, 𝕎 R → 𝕎 R` that maps Witt vectors to Witt vectors over arbitrary base rings
@@ -228,15 +226,20 @@ class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop wh
     ∃ φ : ℕ → MvPolynomial ℕ ℤ,
       ∀ ⦃R⦄ [CommRing R] (x : 𝕎 R), (f x).coeff = fun n => aeval x.coeff (φ n)
 #align witt_vector.is_poly WittVector.IsPoly
+-/
 
+#print WittVector.idIsPoly /-
 /-- The identity function on Witt vectors is a polynomial function. -/
 instance idIsPoly : IsPoly p fun _ _ => id :=
   ⟨⟨X, by intros; simp only [aeval_X, id]⟩⟩
 #align witt_vector.id_is_poly WittVector.idIsPoly
+-/
 
+#print WittVector.idIsPolyI' /-
 instance idIsPolyI' : IsPoly p fun _ _ a => a :=
   WittVector.idIsPoly _
 #align witt_vector.id_is_poly_i' WittVector.idIsPolyI'
+-/
 
 namespace IsPoly
 
@@ -278,6 +281,7 @@ theorem ext {f g} (hf : IsPoly p f) (hg : IsPoly p g)
 
 omit hp
 
+#print WittVector.IsPoly.comp /-
 /-- The composition of polynomial functions is polynomial. -/
 theorem comp {g f} (hg : IsPoly p g) (hf : IsPoly p f) :
     IsPoly p fun R _Rcr => @g R _Rcr ∘ @f R _Rcr :=
@@ -288,9 +292,11 @@ theorem comp {g f} (hg : IsPoly p g) (hf : IsPoly p f) :
   intros
   simp only [aeval_bind₁, Function.comp, hg, hf]
 #align witt_vector.is_poly.comp WittVector.IsPoly.comp
+-/
 
 end IsPoly
 
+#print WittVector.IsPoly₂ /-
 /-- A binary function `f : Π R, 𝕎 R → 𝕎 R → 𝕎 R` on Witt vectors
 is said to be *polynomial* if there is a family of polynomials `φₙ` over `ℤ` such that the `n`th
 coefficient of `f x y` is given by evaluating `φₙ` at the coefficients of `x` and `y`.
@@ -307,9 +313,11 @@ class IsPoly₂ (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R → 
     ∃ φ : ℕ → MvPolynomial (Fin 2 × ℕ) ℤ,
       ∀ ⦃R⦄ [CommRing R] (x y : 𝕎 R), (f x y).coeff = fun n => peval (φ n) ![x.coeff, y.coeff]
 #align witt_vector.is_poly₂ WittVector.IsPoly₂
+-/
 
 variable {p}
 
+#print WittVector.IsPoly₂.comp /-
 /-- The composition of polynomial functions is polynomial. -/
 theorem IsPoly₂.comp {h f g} (hh : IsPoly₂ p h) (hf : IsPoly p f) (hg : IsPoly p g) :
     IsPoly₂ p fun R _Rcr x y => h (f x) (g y) :=
@@ -334,7 +342,9 @@ theorem IsPoly₂.comp {h f g} (hh : IsPoly₂ p h) (hf : IsPoly p f) (hg : IsPo
     simp only [aeval_eq_eval₂_hom, eval₂_hom_rename, Function.comp, Matrix.cons_val_zero,
       Matrix.head_cons, Matrix.cons_val_one]
 #align witt_vector.is_poly₂.comp WittVector.IsPoly₂.comp
+-/
 
+#print WittVector.IsPoly.comp₂ /-
 /-- The composition of a polynomial function with a binary polynomial function is polynomial. -/
 theorem IsPoly.comp₂ {g f} (hg : IsPoly p g) (hf : IsPoly₂ p f) :
     IsPoly₂ p fun R _Rcr x y => g (f x y) :=
@@ -345,7 +355,9 @@ theorem IsPoly.comp₂ {g f} (hg : IsPoly p g) (hf : IsPoly₂ p f) :
   intros
   simp only [peval, aeval_bind₁, Function.comp, hg, hf]
 #align witt_vector.is_poly.comp₂ WittVector.IsPoly.comp₂
+-/
 
+#print WittVector.IsPoly₂.diag /-
 /-- The diagonal `λ x, f x x` of a polynomial function `f` is polynomial. -/
 theorem IsPoly₂.diag {f} (hf : IsPoly₂ p f) : IsPoly p fun R _Rcr x => f x x :=
   by
@@ -357,6 +369,7 @@ theorem IsPoly₂.diag {f} (hf : IsPoly₂ p f) : IsPoly p fun R _Rcr x => f x x
   ext ⟨i, k⟩;
   fin_cases i <;> simp only [Matrix.head_cons, aeval_X, Matrix.cons_val_zero, Matrix.cons_val_one]
 #align witt_vector.is_poly₂.diag WittVector.IsPoly₂.diag
+-/
 
 open Tactic
 
@@ -477,6 +490,7 @@ Users are expected to use the non-instance versions manually.
 -/
 
 
+#print WittVector.negIsPoly /-
 /-- The additive negation is a polynomial function on Witt vectors. -/
 @[is_poly]
 theorem negIsPoly : IsPoly p fun R _ => @Neg.neg (𝕎 R) _ :=
@@ -486,15 +500,18 @@ theorem negIsPoly : IsPoly p fun R _ => @Neg.neg (𝕎 R) _ :=
       apply eval₂_hom_congr rfl _ rfl
       ext ⟨i, k⟩; fin_cases i; rfl⟩⟩
 #align witt_vector.neg_is_poly WittVector.negIsPoly
+-/
 
 section ZeroOne
 
+#print WittVector.zeroIsPoly /-
 /- To avoid a theory of 0-ary functions (a.k.a. constants)
 we model them as constant unary functions. -/
 /-- The function that is constantly zero on Witt vectors is a polynomial function. -/
 instance zeroIsPoly : IsPoly p fun _ _ _ => 0 :=
   ⟨⟨0, by intros; funext n; simp only [Pi.zero_apply, AlgHom.map_zero, zero_coeff]⟩⟩
 #align witt_vector.zero_is_poly WittVector.zeroIsPoly
+-/
 
 @[simp]
 theorem bind₁_zero_wittPolynomial (n : ℕ) :
@@ -524,6 +541,7 @@ theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomi
   · rw [Finset.mem_range]; decide
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
 
+#print WittVector.oneIsPoly /-
 /-- The function that is constantly one on Witt vectors is a polynomial function. -/
 instance oneIsPoly : IsPoly p fun _ _ _ => 1 :=
   ⟨⟨onePoly, by
@@ -533,22 +551,27 @@ instance oneIsPoly : IsPoly p fun _ _ _ => 1 :=
         simp only [one_poly, Nat.succ_pos', one_coeff_eq_of_pos, if_neg n.succ_ne_zero,
           AlgHom.map_zero]⟩⟩
 #align witt_vector.one_is_poly WittVector.oneIsPoly
+-/
 
 end ZeroOne
 
 omit hp
 
+#print WittVector.addIsPoly₂ /-
 /-- Addition of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem addIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
   ⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩
 #align witt_vector.add_is_poly₂ WittVector.addIsPoly₂
+-/
 
+#print WittVector.mulIsPoly₂ /-
 /-- Multiplication of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
   ⟨⟨wittMul p, by intros; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩
 #align witt_vector.mul_is_poly₂ WittVector.mulIsPoly₂
+-/
 
 include hp
 
@@ -574,19 +597,23 @@ instance [Fact p.Prime] : Inhabited (IsPoly₂ p _) :=
 
 variable {p}
 
+#print WittVector.IsPoly₂.compLeft /-
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the first argument is polynomial. -/
 theorem compLeft {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
     IsPoly₂ p fun R _Rcr x y => g (f x) y :=
   hg.comp hf (WittVector.idIsPoly _)
 #align witt_vector.is_poly₂.comp_left WittVector.IsPoly₂.compLeft
+-/
 
+#print WittVector.IsPoly₂.compRight /-
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the second argument is polynomial. -/
 theorem compRight {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
     IsPoly₂ p fun R _Rcr x y => g x (f y) :=
   hg.comp (WittVector.idIsPoly p) hf
 #align witt_vector.is_poly₂.comp_right WittVector.IsPoly₂.compRight
+-/
 
 include hp

168ad7fc

bump to nightly-2023-06-05-12

mathlib commit https://github.com/leanprover-community/mathlib/commit/13361559d66b84f80b6d5a1c4a26aa5054766725

d07076be

Diff

@@ -540,15 +540,15 @@ omit hp
 
 /-- Addition of Witt vectors is a polynomial function. -/
 @[is_poly]
-theorem add_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
+theorem addIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
   ⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩
-#align witt_vector.add_is_poly₂ WittVector.add_isPoly₂
+#align witt_vector.add_is_poly₂ WittVector.addIsPoly₂
 
 /-- Multiplication of Witt vectors is a polynomial function. -/
 @[is_poly]
-theorem mul_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
+theorem mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
   ⟨⟨wittMul p, by intros; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩
-#align witt_vector.mul_is_poly₂ WittVector.mul_isPoly₂
+#align witt_vector.mul_is_poly₂ WittVector.mulIsPoly₂
 
 include hp
 
@@ -570,23 +570,23 @@ namespace IsPoly₂
 omit hp
 
 instance [Fact p.Prime] : Inhabited (IsPoly₂ p _) :=
-  ⟨add_isPoly₂⟩
+  ⟨addIsPoly₂⟩
 
 variable {p}
 
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the first argument is polynomial. -/
-theorem comp_left {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
+theorem compLeft {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
     IsPoly₂ p fun R _Rcr x y => g (f x) y :=
   hg.comp hf (WittVector.idIsPoly _)
-#align witt_vector.is_poly₂.comp_left WittVector.IsPoly₂.comp_left
+#align witt_vector.is_poly₂.comp_left WittVector.IsPoly₂.compLeft
 
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the second argument is polynomial. -/
-theorem comp_right {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
+theorem compRight {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
     IsPoly₂ p fun R _Rcr x y => g x (f y) :=
   hg.comp (WittVector.idIsPoly p) hf
-#align witt_vector.is_poly₂.comp_right WittVector.IsPoly₂.comp_right
+#align witt_vector.is_poly₂.comp_right WittVector.IsPoly₂.compRight
 
 include hp

168ad7fc

bump to nightly-2023-06-01-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/cca40788df1b8755d5baf17ab2f27dacc2e17acb

b9c87c70

Diff

@@ -189,7 +189,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq' (f g : ℕ → MvPolynomial (idx × 
   by
   ext1 n
   apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
-  rw [← Function.funext_iff] at h
+  rw [← Function.funext_iff] at h 
   replace h :=
     congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
@@ -201,7 +201,7 @@ theorem poly_eq_of_wittPolynomial_bind_eq (f g : ℕ → MvPolynomial ℕ ℤ)
   by
   ext1 n
   apply MvPolynomial.map_injective (Int.castRingHom ℚ) Int.cast_injective
-  rw [← Function.funext_iff] at h
+  rw [← Function.funext_iff] at h 
   replace h :=
     congr_arg (fun fam => bind₁ (MvPolynomial.map (Int.castRingHom ℚ) ∘ fam) (xInTermsOfW p ℚ n)) h
   simpa only [Function.comp, map_bind₁, map_wittPolynomial, ← bind₁_bind₁,
@@ -231,7 +231,7 @@ class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop wh
 
 /-- The identity function on Witt vectors is a polynomial function. -/
 instance idIsPoly : IsPoly p fun _ _ => id :=
-  ⟨⟨X, by intros ; simp only [aeval_X, id]⟩⟩
+  ⟨⟨X, by intros; simp only [aeval_X, id]⟩⟩
 #align witt_vector.id_is_poly WittVector.idIsPoly
 
 instance idIsPolyI' : IsPoly p fun _ _ a => a :=
@@ -263,7 +263,7 @@ theorem ext {f g} (hf : IsPoly p f) (hg : IsPoly p g)
   intro x
   simp only [hom_bind₁]
   specialize h (ULift ℤ) (mk p fun i => ⟨x i⟩) k
-  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h
+  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h 
   apply (ulift.ring_equiv.symm : ℤ ≃+* _).Injective
   simp only [← RingEquiv.coe_toRingHom, map_eval₂_hom]
   convert h using 1
@@ -351,7 +351,7 @@ theorem IsPoly₂.diag {f} (hf : IsPoly₂ p f) : IsPoly p fun R _Rcr x => f x x
   by
   obtain ⟨φ, hf⟩ := hf
   refine' ⟨⟨fun n => bind₁ (uncurry ![X, X]) (φ n), _⟩⟩
-  intros ; funext n
+  intros; funext n
   simp only [hf, peval, uncurry, aeval_bind₁]
   apply eval₂_hom_congr rfl _ rfl
   ext ⟨i, k⟩;
@@ -481,7 +481,7 @@ Users are expected to use the non-instance versions manually.
 @[is_poly]
 theorem negIsPoly : IsPoly p fun R _ => @Neg.neg (𝕎 R) _ :=
   ⟨⟨fun n => rename Prod.snd (wittNeg p n), by
-      intros ; funext n
+      intros; funext n
       rw [neg_coeff, aeval_eq_eval₂_hom, eval₂_hom_rename]
       apply eval₂_hom_congr rfl _ rfl
       ext ⟨i, k⟩; fin_cases i; rfl⟩⟩
@@ -493,7 +493,7 @@ section ZeroOne
 we model them as constant unary functions. -/
 /-- The function that is constantly zero on Witt vectors is a polynomial function. -/
 instance zeroIsPoly : IsPoly p fun _ _ _ => 0 :=
-  ⟨⟨0, by intros ; funext n; simp only [Pi.zero_apply, AlgHom.map_zero, zero_coeff]⟩⟩
+  ⟨⟨0, by intros; funext n; simp only [Pi.zero_apply, AlgHom.map_zero, zero_coeff]⟩⟩
 #align witt_vector.zero_is_poly WittVector.zeroIsPoly
 
 @[simp]
@@ -527,7 +527,7 @@ theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomi
 /-- The function that is constantly one on Witt vectors is a polynomial function. -/
 instance oneIsPoly : IsPoly p fun _ _ _ => 1 :=
   ⟨⟨onePoly, by
-      intros ; funext n; cases n
+      intros; funext n; cases n
       · simp only [one_poly, if_true, eq_self_iff_true, one_coeff_zero, AlgHom.map_one]
       ·
         simp only [one_poly, Nat.succ_pos', one_coeff_eq_of_pos, if_neg n.succ_ne_zero,
@@ -541,13 +541,13 @@ omit hp
 /-- Addition of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem add_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
-  ⟨⟨wittAdd p, by intros ; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩
+  ⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩
 #align witt_vector.add_is_poly₂ WittVector.add_isPoly₂
 
 /-- Multiplication of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem mul_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
-  ⟨⟨wittMul p, by intros ; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩
+  ⟨⟨wittMul p, by intros; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩
 #align witt_vector.mul_is_poly₂ WittVector.mul_isPoly₂
 
 include hp
@@ -607,7 +607,7 @@ theorem ext {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
   intro x
   simp only [hom_bind₁]
   specialize h (ULift ℤ) (mk p fun i => ⟨x (0, i)⟩) (mk p fun i => ⟨x (1, i)⟩) k
-  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h
+  simp only [ghost_component_apply, aeval_eq_eval₂_hom] at h 
   apply (ulift.ring_equiv.symm : ℤ ≃+* _).Injective
   simp only [← RingEquiv.coe_toRingHom, map_eval₂_hom]
   convert h using 1
@@ -637,8 +637,12 @@ theorem map {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎 R) :
 
 end IsPoly₂
 
-attribute [ghost_simps]
-  AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map_mul AlgHom.map_sub AlgHom.map_neg AlgHom.id_apply map_natCast RingHom.map_zero RingHom.map_one RingHom.map_mul RingHom.map_add RingHom.map_sub RingHom.map_neg RingHom.id_apply mul_add add_mul add_zero zero_add mul_one one_mul MulZeroClass.mul_zero MulZeroClass.zero_mul Nat.succ_ne_zero add_tsub_cancel_right Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff forall₃_true_iff
+attribute [ghost_simps] AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map_mul AlgHom.map_sub
+  AlgHom.map_neg AlgHom.id_apply map_natCast RingHom.map_zero RingHom.map_one RingHom.map_mul
+  RingHom.map_add RingHom.map_sub RingHom.map_neg RingHom.id_apply mul_add add_mul add_zero zero_add
+  mul_one one_mul MulZeroClass.mul_zero MulZeroClass.zero_mul Nat.succ_ne_zero add_tsub_cancel_right
+  Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff
+  forall₃_true_iff
 
 end WittVector

168ad7fc

bump to nightly-2023-05-28-04

mathlib commit https://github.com/leanprover-community/mathlib/commit/917c3c072e487b3cccdbfeff17e75b40e45f66cb

6797a637

Diff

@@ -231,9 +231,7 @@ class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop wh
 
 /-- The identity function on Witt vectors is a polynomial function. -/
 instance idIsPoly : IsPoly p fun _ _ => id :=
-  ⟨⟨X, by
-      intros
-      simp only [aeval_X, id]⟩⟩
+  ⟨⟨X, by intros ; simp only [aeval_X, id]⟩⟩
 #align witt_vector.id_is_poly WittVector.idIsPoly
 
 instance idIsPolyI' : IsPoly p fun _ _ a => a :=
@@ -495,10 +493,7 @@ section ZeroOne
 we model them as constant unary functions. -/
 /-- The function that is constantly zero on Witt vectors is a polynomial function. -/
 instance zeroIsPoly : IsPoly p fun _ _ _ => 0 :=
-  ⟨⟨0, by
-      intros
-      funext n
-      simp only [Pi.zero_apply, AlgHom.map_zero, zero_coeff]⟩⟩
+  ⟨⟨0, by intros ; funext n; simp only [Pi.zero_apply, AlgHom.map_zero, zero_coeff]⟩⟩
 #align witt_vector.zero_is_poly WittVector.zeroIsPoly
 
 @[simp]
@@ -526,8 +521,7 @@ theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomi
   · intro i hi hi0
     simp only [one_poly, if_neg hi0, zero_pow (pow_pos hp.1.Pos _), MulZeroClass.mul_zero,
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
-  · rw [Finset.mem_range]
-    decide
+  · rw [Finset.mem_range]; decide
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
 
 /-- The function that is constantly one on Witt vectors is a polynomial function. -/
@@ -547,19 +541,13 @@ omit hp
 /-- Addition of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem add_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
-  ⟨⟨wittAdd p, by
-      intros
-      dsimp only [WittVector.hasAdd]
-      simp [eval]⟩⟩
+  ⟨⟨wittAdd p, by intros ; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩
 #align witt_vector.add_is_poly₂ WittVector.add_isPoly₂
 
 /-- Multiplication of Witt vectors is a polynomial function. -/
 @[is_poly]
 theorem mul_isPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
-  ⟨⟨wittMul p, by
-      intros
-      dsimp only [WittVector.hasMul]
-      simp [eval]⟩⟩
+  ⟨⟨wittMul p, by intros ; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩
 #align witt_vector.mul_is_poly₂ WittVector.mul_isPoly₂
 
 include hp

168ad7fc

bump to nightly-2023-03-15-10

mathlib commit https://github.com/leanprover-community/mathlib/commit/1a313d8bba1bad05faba71a4a4e9742ab5bd9efd

f73428b0

Diff

@@ -231,7 +231,7 @@ class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop wh
 
 /-- The identity function on Witt vectors is a polynomial function. -/
 instance idIsPoly : IsPoly p fun _ _ => id :=
-  ⟨⟨x, by
+  ⟨⟨X, by
       intros
       simp only [aeval_X, id]⟩⟩
 #align witt_vector.id_is_poly WittVector.idIsPoly

168ad7fc

bump to nightly-2023-03-11-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/3180fab693e2cee3bff62675571264cb8778b212

cd44fb92

Diff

@@ -524,8 +524,8 @@ theorem bind₁_onePoly_wittPolynomial (n : ℕ) : bind₁ onePoly (wittPolynomi
     simp only [one_poly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
   · intro i hi hi0
-    simp only [one_poly, if_neg hi0, zero_pow (pow_pos hp.1.Pos _), mul_zero, AlgHom.map_pow,
-      bind₁_X_right, AlgHom.map_mul]
+    simp only [one_poly, if_neg hi0, zero_pow (pow_pos hp.1.Pos _), MulZeroClass.mul_zero,
+      AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]
     decide
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
@@ -650,7 +650,7 @@ theorem map {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎 R) :
 end IsPoly₂
 
 attribute [ghost_simps]
-  AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map_mul AlgHom.map_sub AlgHom.map_neg AlgHom.id_apply map_natCast RingHom.map_zero RingHom.map_one RingHom.map_mul RingHom.map_add RingHom.map_sub RingHom.map_neg RingHom.id_apply mul_add add_mul add_zero zero_add mul_one one_mul mul_zero zero_mul Nat.succ_ne_zero add_tsub_cancel_right Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff forall₃_true_iff
+  AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map_mul AlgHom.map_sub AlgHom.map_neg AlgHom.id_apply map_natCast RingHom.map_zero RingHom.map_one RingHom.map_mul RingHom.map_add RingHom.map_sub RingHom.map_neg RingHom.id_apply mul_add add_mul add_zero zero_add mul_one one_mul MulZeroClass.mul_zero MulZeroClass.zero_mul Nat.succ_ne_zero add_tsub_cancel_right Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff forall₃_true_iff
 
 end WittVector

168ad7fc

bump to nightly-2023-02-21-16

mathlib commit https://github.com/leanprover-community/mathlib/commit/bd9851ca476957ea4549eb19b40e7b5ade9428cc

1107b979

Changes in mathlib4

mathlib3

mathlib4

48fb5b52

chore: remove a few miscellaneous now-resolved porting notes (#12127)

fd252837

Diff

@@ -188,7 +188,7 @@ theorem ext [Fact p.Prime] {f g} (hf : IsPoly p f) (hg : IsPoly p g)
   simp only [← RingEquiv.coe_toRingHom, map_eval₂Hom]
   convert h using 1
   all_goals
-    --  porting note: this proof started with `funext i`
+    -- porting note: this proof started with `funext i`
     simp only [hf, hg, MvPolynomial.eval, map_eval₂Hom]
     apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
     ext1
@@ -277,7 +277,7 @@ instance IsPoly₂.diag {f} [hf : IsPoly₂ p f] : IsPoly p fun R _Rcr x => f x
   ext ⟨i, k⟩;
   fin_cases i <;>
     simp only [Matrix.head_cons, aeval_X, Matrix.cons_val_zero, Matrix.cons_val_one] <;>
-    --  porting note: the end of the proof was added in the port.
+    -- porting note: added these lines
     open Matrix in
     simp only [Fin.mk_zero, Fin.mk_one, cons_val', empty_val', cons_val_fin_one, cons_val_zero,
       aeval_X, head_fin_const, cons_val_one]
@@ -320,7 +320,6 @@ def onePoly (n : ℕ) : MvPolynomial ℕ ℤ :=
 @[simp]
 theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
     bind₁ onePoly (wittPolynomial p ℤ n) = 1 := by
-  ext  -- Porting note: `ext` was not in the mathport output.
   rw [wittPolynomial_eq_sum_C_mul_X_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
   · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
@@ -350,15 +349,15 @@ end ZeroOne
 /-- Addition of Witt vectors is a polynomial function. -/
 -- Porting note: replaced `@[is_poly]` with `instance`.
 instance addIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
-  --  porting note: the proof was
-  --  `⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩`
+  -- porting note: the proof was
+  -- `⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩`
   ⟨⟨wittAdd p, by intros; ext; exact add_coeff _ _ _⟩⟩
 #align witt_vector.add_is_poly₂ WittVector.addIsPoly₂
 
 /-- Multiplication of Witt vectors is a polynomial function. -/
 -- Porting note: replaced `@[is_poly]` with `instance`.
 instance mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
-  --  porting note: the proof was
+  -- porting note: the proof was
   -- `⟨⟨wittMul p, by intros; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩`
   ⟨⟨wittMul p, by intros; ext; exact mul_coeff _ _ _⟩⟩
 #align witt_vector.mul_is_poly₂ WittVector.mulIsPoly₂
@@ -379,7 +378,7 @@ theorem IsPoly.map [Fact p.Prime] {f} (hf : IsPoly p f) (g : R →+* S) (x : 
 
 namespace IsPoly₂
 
---  porting note: the argument `(fun _ _ => (· + ·))` to `IsPoly₂` was just `_`.
+-- porting note: the argument `(fun _ _ => (· + ·))` to `IsPoly₂` was just `_`.
 instance [Fact p.Prime] : Inhabited (IsPoly₂ p (fun _ _ => (· + ·))) :=
   ⟨addIsPoly₂⟩
 
@@ -408,7 +407,7 @@ theorem ext [Fact p.Prime] {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
   intros
   ext n
   rw [hf, hg, poly_eq_of_wittPolynomial_bind_eq' p φ ψ]
-  --  porting note: `clear x y` does not work, since `x, y` are now hygienic
+  -- porting note: `clear x y` does not work, since `x, y` are now hygienic
   intro k
   apply MvPolynomial.funext
   intro x
@@ -419,7 +418,7 @@ theorem ext [Fact p.Prime] {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
   simp only [← RingEquiv.coe_toRingHom, map_eval₂Hom]
   convert h using 1
   all_goals
-    --  porting note: this proof started with `funext i`
+    -- porting note: this proof started with `funext i`
     simp only [hf, hg, MvPolynomial.eval, map_eval₂Hom]
     apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
     ext1

48fb5b52

move(Polynomial): Move out of Data (#11751)

Polynomial and MvPolynomial are algebraic objects, hence should be under Algebra (or at least not under Data)

56e439ec

Diff

@@ -3,9 +3,9 @@ Copyright (c) 2020 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 -/
+import Mathlib.Algebra.MvPolynomial.Funext
 import Mathlib.Algebra.Ring.ULift
 import Mathlib.RingTheory.WittVector.Basic
-import Mathlib.Data.MvPolynomial.Funext
 
 #align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
 /-!

48fb5b52

style: homogenise porting notes (#11145)

Homogenises porting notes via capitalisation and addition of whitespace.

It makes the following changes:

converts "--porting note" into "-- Porting note";
converts "porting note" into "Porting note".

8be0b69c

Diff

@@ -247,7 +247,7 @@ instance IsPoly₂.comp {h f g} [hh : IsPoly₂ p h] [hf : IsPoly p f] [hg : IsP
   fin_cases i <;>
     simp only [aeval_eq_eval₂Hom, eval₂Hom_rename, Function.comp, Matrix.cons_val_zero,
       Matrix.head_cons, Matrix.cons_val_one]
-    -- porting note: added the rest of the proof.
+    -- Porting note: added the rest of the proof.
     <;>
     open Matrix in
     simp only [algebraMap_int_eq, coe_eval₂Hom, Fin.mk_zero, Fin.mk_one, cons_val', empty_val',
@@ -320,7 +320,7 @@ def onePoly (n : ℕ) : MvPolynomial ℕ ℤ :=
 @[simp]
 theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
     bind₁ onePoly (wittPolynomial p ℤ n) = 1 := by
-  ext  -- porting note: `ext` was not in the mathport output.
+  ext  -- Porting note: `ext` was not in the mathport output.
   rw [wittPolynomial_eq_sum_C_mul_X_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
   · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
@@ -328,7 +328,7 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
     simp only [onePoly, if_neg hi0, zero_pow (pow_ne_zero _ hp.1.ne_zero), mul_zero,
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]
-    -- porting note: was `decide`
+    -- Porting note: was `decide`
     intro h
     simp only [add_pos_iff, zero_lt_one, or_true, not_true_eq_false] at h
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
@@ -337,9 +337,9 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
 instance oneIsPoly [Fact p.Prime] : IsPoly p fun _ _ _ => 1 :=
   ⟨⟨onePoly, by
       intros; funext n; cases n
-      · -- porting note: was `simp only [...]` but with slightly different `[...]`.
+      · -- Porting note: was `simp only [...]` but with slightly different `[...]`.
         simp only [Nat.zero_eq, lt_self_iff_false, one_coeff_zero, onePoly, ite_true, map_one]
-      · -- porting note: was `simp only [...]` but with slightly different `[...]`.
+      · -- Porting note: was `simp only [...]` but with slightly different `[...]`.
         simp only [Nat.succ_pos', one_coeff_eq_of_pos, onePoly, Nat.succ_ne_zero, ite_false,
           map_zero]
   ⟩⟩
@@ -373,7 +373,7 @@ theorem IsPoly.map [Fact p.Prime] {f} (hf : IsPoly p f) (g : R →+* S) (x : 
   ext n
   simp only [map_coeff, hf, map_aeval]
   apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
-  ext  -- porting note: this `ext` was not present in the mathport output
+  ext  -- Porting note: this `ext` was not present in the mathport output
   simp only [map_coeff]
 #align witt_vector.is_poly.map WittVector.IsPoly.map
 
@@ -439,7 +439,7 @@ theorem map [Fact p.Prime] {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎
   apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
   try ext ⟨i, k⟩; fin_cases i
   all_goals simp only [map_coeff, Matrix.cons_val_zero, Matrix.head_cons, Matrix.cons_val_one]
-  -- porting note: added the rest of the proof
+  -- Porting note: added the rest of the proof
   all_goals
     simp only [Fin.mk_zero, Fin.mk_one, Matrix.cons_val', Matrix.empty_val', Matrix.cons_val_one,
       Matrix.cons_val_fin_one, Matrix.cons_val_zero, map_coeff, Matrix.head_fin_const]

48fb5b52

chore: classify added instance porting notes (#11085)

Classifies by adding issue number #10754 to porting notes claiming anything semantically equivalent to:

"added instance"
"new instance"
"adding instance"
"had to add this instance manually"

8f422f3d

Diff

@@ -197,7 +197,7 @@ theorem ext [Fact p.Prime] {f g} (hf : IsPoly p f) (hg : IsPoly p g)
 #align witt_vector.is_poly.ext WittVector.IsPoly.ext
 
 /-- The composition of polynomial functions is polynomial. -/
--- Porting note: made this an instance
+-- Porting note (#10754): made this an instance
 instance comp {g f} [hg : IsPoly p g] [hf : IsPoly p f] :
     IsPoly p fun R _Rcr => @g R _Rcr ∘ @f R _Rcr := by
   obtain ⟨φ, hf⟩ := hf
@@ -229,7 +229,7 @@ class IsPoly₂ (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R → 
 variable {p}
 
 /-- The composition of polynomial functions is polynomial. -/
--- Porting note: made this an instance
+-- Porting note (#10754): made this an instance
 instance IsPoly₂.comp {h f g} [hh : IsPoly₂ p h] [hf : IsPoly p f] [hg : IsPoly p g] :
     IsPoly₂ p fun R _Rcr x y => h (f x) (g y) := by
   obtain ⟨φ, hf⟩ := hf
@@ -256,7 +256,7 @@ instance IsPoly₂.comp {h f g} [hh : IsPoly₂ p h] [hf : IsPoly p f] [hg : IsP
 #align witt_vector.is_poly₂.comp WittVector.IsPoly₂.comp
 
 /-- The composition of a polynomial function with a binary polynomial function is polynomial. -/
--- Porting note: made this an instance
+-- Porting note (#10754): made this an instance
 instance IsPoly.comp₂ {g f} [hg : IsPoly p g] [hf : IsPoly₂ p f] :
     IsPoly₂ p fun R _Rcr x y => g (f x y) := by
   obtain ⟨φ, hf⟩ := hf
@@ -267,7 +267,7 @@ instance IsPoly.comp₂ {g f} [hg : IsPoly p g] [hf : IsPoly₂ p f] :
 #align witt_vector.is_poly.comp₂ WittVector.IsPoly.comp₂
 
 /-- The diagonal `fun x ↦f x x` of a polynomial function `f` is polynomial. -/
--- Porting note: made this an instance
+-- Porting note (#10754): made this an instance
 instance IsPoly₂.diag {f} [hf : IsPoly₂ p f] : IsPoly p fun R _Rcr x => f x x := by
   obtain ⟨φ, hf⟩ := hf
   refine' ⟨⟨fun n => bind₁ (uncurry ![X, X]) (φ n), _⟩⟩

48fb5b52

chore: replace Lean 3 syntax λ x, in doc comments (#10727)

Use Lean 4 syntax fun x ↦ instead, matching the style guide. This is close to exhaustive for doc comments; mathlib has about 460 remaining uses of λ (not all in Lean 3 syntax).

4a99b7e2

Diff

@@ -266,7 +266,7 @@ instance IsPoly.comp₂ {g f} [hg : IsPoly p g] [hf : IsPoly₂ p f] :
   simp only [peval, aeval_bind₁, Function.comp, hg, hf]
 #align witt_vector.is_poly.comp₂ WittVector.IsPoly.comp₂
 
-/-- The diagonal `λ x, f x x` of a polynomial function `f` is polynomial. -/
+/-- The diagonal `fun x ↦f x x` of a polynomial function `f` is polynomial. -/
 -- Porting note: made this an instance
 instance IsPoly₂.diag {f} [hf : IsPoly₂ p f] : IsPoly p fun R _Rcr x => f x x := by
   obtain ⟨φ, hf⟩ := hf

48fb5b52

feat: The support of f ^ n (#9617)

This involves moving lemmas from Algebra.GroupPower.Ring to Algebra.GroupWithZero.Basic and changing some 0 < n assumptions to n ≠ 0.

From LeanAPAP

9d1a7d26

Diff

@@ -325,7 +325,7 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
   · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
   · intro i _hi hi0
-    simp only [onePoly, if_neg hi0, zero_pow (pow_pos hp.1.pos _), mul_zero,
+    simp only [onePoly, if_neg hi0, zero_pow (pow_ne_zero _ hp.1.ne_zero), mul_zero,
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]
     -- porting note: was `decide`

48fb5b52

chore: bump to v4.3.0-rc2 (#8366)

PR contents

This is the supremum of

#8284
#8056
#8023
#8332
#8226 (already approved)
#7834 (already approved)

along with some minor fixes from failures on nightly-testing as Mathlib master is merged into it.

Note that some PRs for changes that are already compatible with the current toolchain and will be necessary have already been split out: #8380.

I am hopeful that in future we will be able to progressively merge adaptation PRs into a bump/v4.X.0 branch, so we never end up with a "big merge" like this. However one of these adaptation PRs (#8056) predates my new scheme for combined CI, and it wasn't possible to keep that PR viable in the meantime.

Lean PRs involved in this bump

In particular this includes adjustments for the Lean PRs

leanprover/lean4#2778

We can get rid of all the

local macro_rules | `($x ^ $y) => `(HPow.hPow $x $y) -- Porting note: See issue [lean4#2220](https://github.com/leanprover/lean4/pull/2220)

macros across Mathlib (and in any projects that want to write natural number powers of reals).

leanprover/lean4#2722

Changes the default behaviour of simp to (config := {decide := false}). This makes simp (and consequentially norm_num) less powerful, but also more consistent, and less likely to blow up in long failures. This requires a variety of changes: changing some previously by simp or norm_num to decide or rfl, or adding (config := {decide := true}).

leanprover/lean4#2783

This changed the behaviour of simp so that simp [f] will only unfold "fully applied" occurrences of f. The old behaviour can be recovered with simp (config := { unfoldPartialApp := true }). We may in future add a syntax for this, e.g. simp [!f]; please provide feedback! In the meantime, we have made the following changes:

switching to using explicit lemmas that have the intended level of application
(config := { unfoldPartialApp := true }) in some places, to recover the old behaviour
Using @[eqns] to manually adjust the equation lemmas for a particular definition, recovering the old behaviour just for that definition. See #8371, where we do this for Function.comp and Function.flip.

This change in Lean may require further changes down the line (e.g. adding the !f syntax, and/or upstreaming the special treatment for Function.comp and Function.flip, and/or removing this special treatment). Please keep an open and skeptical mind about these changes!

Co-authored-by: leanprover-community-mathlib4-bot <leanprover-community-mathlib4-bot@users.noreply.github.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Mauricio Collares <mauricio@collares.org>

40b64f79

Diff

@@ -240,7 +240,8 @@ instance IsPoly₂.comp {h f g} [hh : IsPoly₂ p h] [hf : IsPoly p f] [hg : IsP
       fun k ↦ rename (Prod.mk (1 : Fin 2)) (ψ k)]) (χ n), _⟩⟩
   intros
   funext n
-  simp only [peval, aeval_bind₁, Function.comp, hh, hf, hg, uncurry]
+  simp (config := { unfoldPartialApp := true }) only [peval, aeval_bind₁, Function.comp, hh, hf, hg,
+    uncurry]
   apply eval₂Hom_congr rfl _ rfl
   ext ⟨i, n⟩
   fin_cases i <;>
@@ -271,7 +272,7 @@ instance IsPoly₂.diag {f} [hf : IsPoly₂ p f] : IsPoly p fun R _Rcr x => f x
   obtain ⟨φ, hf⟩ := hf
   refine' ⟨⟨fun n => bind₁ (uncurry ![X, X]) (φ n), _⟩⟩
   intros; funext n
-  simp only [hf, peval, uncurry, aeval_bind₁]
+  simp (config := { unfoldPartialApp := true }) only [hf, peval, uncurry, aeval_bind₁]
   apply eval₂Hom_congr rfl _ rfl
   ext ⟨i, k⟩;
   fin_cases i <;>
@@ -328,8 +329,8 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]
     -- porting note: was `decide`
-    simp only [add_pos_iff, or_true, not_true, pow_zero, map_one, ge_iff_le, nonpos_iff_eq_zero,
-      tsub_zero, one_mul, gt_iff_lt, IsEmpty.forall_iff]
+    intro h
+    simp only [add_pos_iff, zero_lt_one, or_true, not_true_eq_false] at h
 #align witt_vector.bind₁_one_poly_witt_polynomial WittVector.bind₁_onePoly_wittPolynomial
 
 /-- The function that is constantly one on Witt vectors is a polynomial function. -/
@@ -434,7 +435,7 @@ theorem map [Fact p.Prime] {f} (hf : IsPoly₂ p f) (g : R →+* S) (x y : 𝕎
   -- so that applications do not have to worry about the universe issue
   obtain ⟨φ, hf⟩ := hf
   ext n
-  simp only [map_coeff, hf, map_aeval, peval, uncurry]
+  simp (config := { unfoldPartialApp := true }) only [map_coeff, hf, map_aeval, peval, uncurry]
   apply eval₂Hom_congr (RingHom.ext_int _ _) _ rfl
   try ext ⟨i, k⟩; fin_cases i
   all_goals simp only [map_coeff, Matrix.cons_val_zero, Matrix.head_cons, Matrix.cons_val_one]

48fb5b52

chore: only four spaces for subsequent lines (#7286)

Co-authored-by: Moritz Firsching <firsching@google.com>

0c7d6fa5

Diff

@@ -73,7 +73,7 @@ Any lemma doing "ring equation rewriting" with polynomial functions should be ta
 ```lean
 @[ghost_simps]
 lemma bind₁_frobenius_poly_wittPolynomial (n : ℕ) :
-  bind₁ (frobenius_poly p) (wittPolynomial p ℤ n) = (wittPolynomial p ℤ (n+1))
+    bind₁ (frobenius_poly p) (wittPolynomial p ℤ n) = (wittPolynomial p ℤ (n+1))
 ```
 
 Proofs of identities between polynomial functions will often follow the pattern

48fb5b52

chore: drop MulZeroClass. in mul_zero/zero_mul (#6682)

Search&replace MulZeroClass.mul_zero -> mul_zero, MulZeroClass.zero_mul -> zero_mul.

These were introduced by Mathport, as the full name of mul_zero is actually MulZeroClass.mul_zero (it's exported with the short name).

277dea95

Diff

@@ -324,7 +324,7 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
   · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
   · intro i _hi hi0
-    simp only [onePoly, if_neg hi0, zero_pow (pow_pos hp.1.pos _), MulZeroClass.mul_zero,
+    simp only [onePoly, if_neg hi0, zero_pow (pow_pos hp.1.pos _), mul_zero,
       AlgHom.map_pow, bind₁_X_right, AlgHom.map_mul]
   · rw [Finset.mem_range]
     -- porting note: was `decide`
@@ -449,7 +449,7 @@ end IsPoly₂
 attribute [ghost_simps] AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map_mul AlgHom.map_sub
   AlgHom.map_neg AlgHom.id_apply map_natCast RingHom.map_zero RingHom.map_one RingHom.map_mul
   RingHom.map_add RingHom.map_sub RingHom.map_neg RingHom.id_apply mul_add add_mul add_zero zero_add
-  mul_one one_mul MulZeroClass.mul_zero MulZeroClass.zero_mul Nat.succ_ne_zero add_tsub_cancel_right
+  mul_one one_mul mul_zero zero_mul Nat.succ_ne_zero add_tsub_cancel_right
   Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff
   forall₃_true_iff

48fb5b52

chore: banish Type _ and Sort _ (#6499)

We remove all possible occurences of Type _ and Sort _ in favor of Type* and Sort*.

This has nice performance benefits.

32de3f67

Diff

@@ -94,7 +94,7 @@ namespace WittVector
 
 universe u
 
-variable {p : ℕ} {R S : Type u} {σ idx : Type _} [CommRing R] [CommRing S]
+variable {p : ℕ} {R S : Type u} {σ idx : Type*} [CommRing R] [CommRing S]
 
 local notation "𝕎" => WittVector p -- type as `\bbW`

48fb5b52

chore: script to replace headers with #align_import statements (#5979)

depends on: #5966

Co-authored-by: Eric Wieser <wieser.eric@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

89aa3a3b

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2020 Johan Commelin. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
-
-! This file was ported from Lean 3 source module ring_theory.witt_vector.is_poly
-! leanprover-community/mathlib commit 48fb5b5280e7c81672afc9524185ae994553ebf4
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Algebra.Ring.ULift
 import Mathlib.RingTheory.WittVector.Basic
 import Mathlib.Data.MvPolynomial.Funext
+
+#align_import ring_theory.witt_vector.is_poly from "leanprover-community/mathlib"@"48fb5b5280e7c81672afc9524185ae994553ebf4"
 /-!
 # The `is_poly` predicate

48fb5b52

refactor: move all register_simp_attrs to 1 file (#5681)

There are slight differences between mathlib3 and mathlib4 (different set of attributes, different lemmas are in core/std), so I redid the same refactor instead of forward-porting changes.

mathlib3 PR: leanprover-community/mathlib#19223

ceaa4ecb

Diff

@@ -4,14 +4,13 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johan Commelin, Robert Y. Lewis
 
 ! This file was ported from Lean 3 source module ring_theory.witt_vector.is_poly
-! leanprover-community/mathlib commit 168ad7fc5d8173ad38be9767a22d50b8ecf1cd00
+! leanprover-community/mathlib commit 48fb5b5280e7c81672afc9524185ae994553ebf4
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
 import Mathlib.Algebra.Ring.ULift
 import Mathlib.RingTheory.WittVector.Basic
 import Mathlib.Data.MvPolynomial.Funext
-import Mathlib.RingTheory.WittVector.WittAttributes
 /-!
 # The `is_poly` predicate

168ad7fc

feat: port RingTheory.WittVector.MulCoeff (#5554)

b47e7d28

Diff

@@ -324,7 +324,7 @@ def onePoly (n : ℕ) : MvPolynomial ℕ ℤ :=
 theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
     bind₁ onePoly (wittPolynomial p ℤ n) = 1 := by
   ext  -- porting note: `ext` was not in the mathport output.
-  rw [wittPolynomial_eq_sum_c_mul_x_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
+  rw [wittPolynomial_eq_sum_C_mul_X_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
   · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
   · intro i _hi hi0

168ad7fc

feat: port RingTheory.WittVector.Verschiebung (#4897)

Co-authored-by: Moritz Firsching <firsching@google.com> Co-authored-by: Kyle Miller <kmill31415@gmail.com> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Johan Commelin <johan@commelin.net>

64ec3a13

Diff

@@ -64,11 +64,13 @@ as constant functions and fall under the unary case.
 ## Tactics
 
 There are important metaprograms defined in this file:
-the tactics `ghost_simp` and `ghost_calc` and the attributes `@[is_poly]` and `@[ghost_simps]`.
+the tactics `ghost_simp` and `ghost_calc` and the attribute `@[ghost_simps]`.
 These are used in combination to discharge proofs of identities between polynomial functions.
 
-Any atomic proof of `IsPoly` or `IsPoly₂` (i.e. not taking additional `IsPoly` arguments)
-should be tagged as `@[is_poly]`.
+The `ghost_calc` tactic makes use of the `IsPoly` and `IsPoly₂` typeclass and its instances.
+(In Lean 3, there was an `@[is_poly]` attribute to manage these instances,
+because typeclass resolution did not play well with function composition.
+This no longer seems to be an issue, so that such instances can be defined directly.)
 
 Any lemma doing "ring equation rewriting" with polynomial functions should be tagged
 `@[ghost_simps]`, e.g.
@@ -80,11 +82,9 @@ lemma bind₁_frobenius_poly_wittPolynomial (n : ℕ) :
 
 Proofs of identities between polynomial functions will often follow the pattern
 ```lean
-begin
-  ghost_calc _,
-  <minor preprocessing>,
+  ghost_calc _
+  <minor preprocessing>
   ghost_simp
-end
 ```
 
 ## References
@@ -94,81 +94,14 @@ end
 * [Commelin and Lewis, *Formalizing the Ring of Witt Vectors*][CL21]
 -/
 
-
-/- failed to parenthesize: unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
-[PrettyPrinter.parenthesize.input] (Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr
-     [(Command.docComment "/--" "Simplification rules for ghost equations -/")]
-     "register_simp_attr"
-     `ghost_simps)-/-- unknown constant 'Lean.Meta._root_.Lean.Parser.Command.registerSimpAttr'
---/-- Simplification rules for ghost equations -/ register_simp_attr ghost_simps
-
-/-  --  porting note: todo later
-namespace Tactic
-
-namespace Interactive
-
-/-- A macro for a common simplification when rewriting with ghost component equations. -/
-unsafe def ghost_simp (lems : parse simp_arg_list) : tactic Unit := do
-  tactic.try tactic.intro1
-  simp none none tt (lems ++ [simp_arg_type.symm_expr ``(sub_eq_add_neg)]) [`ghost_simps]
-      (loc.ns [none])
-#align tactic.interactive.ghost_simp tactic.interactive.ghost_simp
-
-/-- `ghost_calc` is a tactic for proving identities between polynomial functions.
-Typically, when faced with a goal like
-```lean
-∀ (x y : 𝕎 R), verschiebung (x * frobenius y) = verschiebung x * y
-```
-you can
-1. call `ghost_calc`
-2. do a small amount of manual work -- maybe nothing, maybe `rintro`, etc
-3. call `ghost_simp`
-
-and this will close the goal.
-
-`ghost_calc` cannot detect whether you are dealing with unary or binary polynomial functions.
-You must give it arguments to determine this.
-If you are proving a universally quantified goal like the above,
-call `ghost_calc _ _`.
-If the variables are introduced already, call `ghost_calc x y`.
-In the unary case, use `ghost_calc _` or `ghost_calc x`.
-
-`ghost_calc` is a light wrapper around type class inference.
-All it does is apply the appropriate extensionality lemma and try to infer the resulting goals.
-This is subtle and Lean's elaborator doesn't like it because of the HO unification involved,
-so it is easier (and prettier) to put it in a tactic script.
--/
-unsafe def ghost_calc (ids' : parse ident_*) : tactic Unit := do
-  let ids ← ids'.mapM fun n => get_local n <|> tactic.intro n
-  let q(@Eq (WittVector _ $(R)) _ _) ← target
-  match ids with
-    | [x] => refine `(is_poly.ext _ _ _ _ $(x))
-    | [x, y] => refine `(is_poly₂.ext _ _ _ _ $(x) $(y))
-    | _ => fail "ghost_calc takes one or two arguments"
-  let nm ←
-    match R with
-      | expr.local_const _ nm _ _ => return nm
-      | _ => get_unused_name `R
-  iterate_exactly 2 apply_instance
-  unfreezingI (tactic.clear' tt [R])
-  introsI <| [nm, .str nm "_inst"] ++ ids'
-  skip
-#align tactic.interactive.ghost_calc tactic.interactive.ghost_calc
-
-end Interactive
-
-end Tactic
--/
-
 namespace WittVector
 
 universe u
 
 variable {p : ℕ} {R S : Type u} {σ idx : Type _} [CommRing R] [CommRing S]
 
-local notation "𝕎" => WittVector p
+local notation "𝕎" => WittVector p -- type as `\bbW`
 
--- type as `\bbW`
 open MvPolynomial
 
 open Function (uncurry)
@@ -213,10 +146,10 @@ coefficient of `f x` is given by evaluating `φₙ` at the coefficients of `x`.
 
 See also `WittVector.IsPoly₂` for the binary variant.
 
-The `ghost_calc` tactic treats `IsPoly` as a type class,
-and the `@[is_poly]` attribute derives certain specialized composition instances
-for declarations of type `IsPoly f`.
-For the most part, users are not expected to treat `IsPoly` as a class.
+The `ghost_calc` tactic makes use of the `IsPoly` and `IsPoly₂` typeclass and its instances.
+(In Lean 3, there was an `@[is_poly]` attribute to manage these instances,
+because typeclass resolution did not play well with function composition.
+This no longer seems to be an issue, so that such instances can be defined directly.)
 -/
 class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop where mk' ::
   poly :
@@ -241,8 +174,7 @@ instance : Inhabited (IsPoly p fun _ _ => id) :=
 variable {p}
 
 theorem ext [Fact p.Prime] {f g} (hf : IsPoly p f) (hg : IsPoly p g)
-    (h :
-      ∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R) (n : ℕ),
+    (h : ∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R) (n : ℕ),
         ghostComponent n (f x) = ghostComponent n (g x)) :
     ∀ (R : Type u) [_Rcr : CommRing R] (x : 𝕎 R), f x = g x := by
   obtain ⟨φ, hf⟩ := hf
@@ -269,7 +201,8 @@ theorem ext [Fact p.Prime] {f g} (hf : IsPoly p f) (hg : IsPoly p g)
 #align witt_vector.is_poly.ext WittVector.IsPoly.ext
 
 /-- The composition of polynomial functions is polynomial. -/
-theorem comp {g f} (hg : IsPoly p g) (hf : IsPoly p f) :
+-- Porting note: made this an instance
+instance comp {g f} [hg : IsPoly p g] [hf : IsPoly p f] :
     IsPoly p fun R _Rcr => @g R _Rcr ∘ @f R _Rcr := by
   obtain ⟨φ, hf⟩ := hf
   obtain ⟨ψ, hg⟩ := hg
@@ -286,10 +219,10 @@ coefficient of `f x y` is given by evaluating `φₙ` at the coefficients of `x`
 
 See also `WittVector.IsPoly` for the unary variant.
 
-The `ghost_calc` tactic treats `IsPoly₂` as a type class,
-and the `@[is_poly]` attribute derives certain specialized composition instances
-for declarations of type `IsPoly₂ f`.
-For the most part, users are not expected to treat `IsPoly₂` as a class.
+The `ghost_calc` tactic makes use of the `IsPoly` and `IsPoly₂` typeclass and its instances.
+(In Lean 3, there was an `@[is_poly]` attribute to manage these instances,
+because typeclass resolution did not play well with function composition.
+This no longer seems to be an issue, so that such instances can be defined directly.)
 -/
 class IsPoly₂ (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R → 𝕎 R) : Prop where mk' ::
   poly :
@@ -300,19 +233,15 @@ class IsPoly₂ (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R → 
 variable {p}
 
 /-- The composition of polynomial functions is polynomial. -/
-theorem IsPoly₂.comp {h f g} (hh : IsPoly₂ p h) (hf : IsPoly p f) (hg : IsPoly p g) :
+-- Porting note: made this an instance
+instance IsPoly₂.comp {h f g} [hh : IsPoly₂ p h] [hf : IsPoly p f] [hg : IsPoly p g] :
     IsPoly₂ p fun R _Rcr x y => h (f x) (g y) := by
   obtain ⟨φ, hf⟩ := hf
   obtain ⟨ψ, hg⟩ := hg
   obtain ⟨χ, hh⟩ := hh
-  refine'
-    ⟨⟨fun n =>
-        bind₁
-          (uncurry <|
-            ![fun k => rename (Prod.mk (0 : Fin 2)) (φ k), fun k =>
-              rename (Prod.mk (1 : Fin 2)) (ψ k)])
-          (χ n),
-        _⟩⟩
+  refine' ⟨⟨fun n ↦ bind₁ (uncurry <|
+    ![fun k ↦ rename (Prod.mk (0 : Fin 2)) (φ k),
+      fun k ↦ rename (Prod.mk (1 : Fin 2)) (ψ k)]) (χ n), _⟩⟩
   intros
   funext n
   simp only [peval, aeval_bind₁, Function.comp, hh, hf, hg, uncurry]
@@ -330,7 +259,8 @@ theorem IsPoly₂.comp {h f g} (hh : IsPoly₂ p h) (hf : IsPoly p f) (hg : IsPo
 #align witt_vector.is_poly₂.comp WittVector.IsPoly₂.comp
 
 /-- The composition of a polynomial function with a binary polynomial function is polynomial. -/
-theorem IsPoly.comp₂ {g f} (hg : IsPoly p g) (hf : IsPoly₂ p f) :
+-- Porting note: made this an instance
+instance IsPoly.comp₂ {g f} [hg : IsPoly p g] [hf : IsPoly₂ p f] :
     IsPoly₂ p fun R _Rcr x y => g (f x y) := by
   obtain ⟨φ, hf⟩ := hf
   obtain ⟨ψ, hg⟩ := hg
@@ -339,142 +269,30 @@ theorem IsPoly.comp₂ {g f} (hg : IsPoly p g) (hf : IsPoly₂ p f) :
   simp only [peval, aeval_bind₁, Function.comp, hg, hf]
 #align witt_vector.is_poly.comp₂ WittVector.IsPoly.comp₂
 
-/-- The diagonal `fun x ↦ f x x` of a polynomial function `f` is polynomial. -/
-theorem IsPoly₂.diag {f} (hf : IsPoly₂ p f) : IsPoly p fun R _Rcr x => f x x := by
+/-- The diagonal `λ x, f x x` of a polynomial function `f` is polynomial. -/
+-- Porting note: made this an instance
+instance IsPoly₂.diag {f} [hf : IsPoly₂ p f] : IsPoly p fun R _Rcr x => f x x := by
   obtain ⟨φ, hf⟩ := hf
   refine' ⟨⟨fun n => bind₁ (uncurry ![X, X]) (φ n), _⟩⟩
   intros; funext n
   simp only [hf, peval, uncurry, aeval_bind₁]
   apply eval₂Hom_congr rfl _ rfl
   ext ⟨i, k⟩;
-  fin_cases i <;> simp only [Matrix.head_cons, aeval_X, Matrix.cons_val_zero, Matrix.cons_val_one]
+  fin_cases i <;>
+    simp only [Matrix.head_cons, aeval_X, Matrix.cons_val_zero, Matrix.cons_val_one] <;>
     --  porting note: the end of the proof was added in the port.
-    <;>
     open Matrix in
     simp only [Fin.mk_zero, Fin.mk_one, cons_val', empty_val', cons_val_fin_one, cons_val_zero,
       aeval_X, head_fin_const, cons_val_one]
 #align witt_vector.is_poly₂.diag WittVector.IsPoly₂.diag
 
-/-  porting note: port later
-open Tactic
-
-namespace Tactic
-
-/-!
-### The `@[is_poly]` attribute
-
-This attribute is used to derive specialized composition instances
-for `IsPoly` and `IsPoly₂` declarations.
--/
-
-/-- If `n` is the name of a lemma with opened type `∀ vars, IsPoly p _`,
-`mk_poly_comp_lemmas n vars p` adds composition instances to the environment
-`n.comp_i` and `n.comp₂_i`.
--/
-unsafe def mk_poly_comp_lemmas (n : Name) (vars : List expr) (p : expr) : tactic Unit := do
-  let c ← mk_const n
-  let appd := vars.foldl expr.app c
-  let tgt_bod ←
-    to_expr ``(fun f [hf : IsPoly $(p) f] => IsPoly.comp $(appd) hf) >>=
-        replace_univ_metas_with_univ_params
-  let tgt_bod ← lambdas vars tgt_bod
-  let tgt_tp ← infer_type tgt_bod
-  let nm := .str n "comp_i"
-  add_decl <| mk_definition nm tgt_tp tgt_tp tgt_bod
-  set_attribute `instance nm
-  let tgt_bod ←
-    to_expr ``(fun f [hf : IsPoly₂ $(p) f] => IsPoly.comp₂ $(appd) hf) >>=
-        replace_univ_metas_with_univ_params
-  let tgt_bod ← lambdas vars tgt_bod
-  let tgt_tp ← infer_type tgt_bod
-  let nm := .str n "comp₂_i"
-  add_decl <| mk_definition nm tgt_tp tgt_tp tgt_bod
-  set_attribute `instance nm
-#align witt_vector.tactic.mk_poly_comp_lemmas witt_vector.tactic.mk_poly_comp_lemmas
-
-/-- If `n` is the name of a lemma with opened type `∀ vars, IsPoly₂ p _`,
-`mk_poly₂_comp_lemmas n vars p` adds composition instances to the environment
-`n.comp₂_i` and `n.comp_diag`.
--/
-unsafe def mk_poly₂_comp_lemmas (n : Name) (vars : List expr) (p : expr) : tactic Unit := do
-  let c ← mk_const n
-  let appd := vars.foldl expr.app c
-  let tgt_bod ←
-    to_expr
-          ``(fun {f g} [hf : IsPoly $(p) f] [hg : IsPoly $(p) g] => IsPoly₂.comp $(appd) hf hg) >>=
-        replace_univ_metas_with_univ_params
-  let tgt_bod ← lambdas vars tgt_bod
-  let tgt_tp ← infer_type tgt_bod >>= simp_lemmas.mk.dsimplify
-  let nm := .str n "comp₂_i"
-  add_decl <| mk_definition nm tgt_tp tgt_tp tgt_bod
-  set_attribute `instance nm
-  let tgt_bod ←
-    to_expr
-          ``(fun {f g} [hf : IsPoly $(p) f] [hg : IsPoly $(p) g] =>
-            (IsPoly₂.comp $(appd) hf hg).diag) >>=
-        replace_univ_metas_with_univ_params
-  let tgt_bod ← lambdas vars tgt_bod
-  let tgt_tp ← infer_type tgt_bod >>= simp_lemmas.mk.dsimplify
-  let nm := .str n "comp_diag"
-  add_decl <| mk_definition nm tgt_tp tgt_tp tgt_bod
-  set_attribute `instance nm
-#align witt_vector.tactic.mk_poly₂_comp_lemmas witt_vector.tactic.mk_poly₂_comp_lemmas
-
-/-- The `after_set` function for `@[is_poly]`. Calls `mk_poly(₂)_comp_lemmas`.
--/
-unsafe def mk_comp_lemmas (n : Name) : tactic Unit := do
-  let d ← get_decl n
-  let (vars, tp) ← open_pis d.type
-  match tp with
-    | q(IsPoly $(p) _) => mk_poly_comp_lemmas n vars p
-    | q(IsPoly₂ $(p) _) => mk_poly₂_comp_lemmas n vars p
-    | _ => fail "@[is_poly] should only be applied to terms of type `IsPoly _ _` or `IsPoly₂ _ _`"
-#align witt_vector.tactic.mk_comp_lemmas witt_vector.tactic.mk_comp_lemmas
-
-/-- `@[is_poly]` is applied to lemmas of the form `IsPoly f φ` or `IsPoly₂ f φ`.
-These lemmas should *not* be tagged as instances, and only atomic `IsPoly` defs should be tagged:
-composition lemmas should not. Roughly speaking, lemmas that take `IsPoly` proofs as arguments
-should not be tagged.
-
-Type class inference struggles with function composition, and the higher order unification problems
-involved in inferring `IsPoly` proofs are complex. The standard style writing these proofs by hand
-doesn't work very well. Instead, we construct the type class hierarchy "under the hood", with
-limited forms of composition.
-
-Applying `@[is_poly]` to a lemma creates a number of instances. Roughly, if the tagged lemma is a
-proof of `IsPoly f φ`, the instances added have the form
-```lean
-∀ g ψ, [IsPoly g ψ] → IsPoly (f ∘ g) _
-```
-Since `f` is fixed in this instance, it restricts the HO unification needed when the instance is
-applied. Composition lemmas relating `IsPoly` with `IsPoly₂` are also added.
-`idIsPoly` is an atomic instance.
-
-The user-written lemmas are not instances. Users should be able to assemble `is_poly` proofs by hand
-"as normal" if the tactic fails.
--/
-@[user_attribute]
-unsafe def isPolyAttr : user_attribute where
-  Name := `IsPoly
-  descr := "Lemmas with this attribute describe the polynomial structure of functions"
-  after_set := some fun n _ _ => mk_comp_lemmas n
-#align witt_vector.tactic.is_poly_attr WittVector.Tactic.isPolyAttr
-
-end Tactic
--/
-
-/-!
-### `IsPoly` instances
-
-These are not declared as instances at the top level,
-but the `@[is_poly]` attribute adds instances based on each one.
-Users are expected to use the non-instance versions manually.
--/
-
+-- Porting note: Lean 4's typeclass inference is sufficiently more powerful that we no longer
+-- need the `@[is_poly]` attribute. Use of the attribute should just be replaced by changing the
+-- theorem to an `instance`.
 
 /-- The additive negation is a polynomial function on Witt vectors. -/
-@[is_poly]
-theorem negIsPoly [Fact p.Prime] : IsPoly p fun R _ => @Neg.neg (𝕎 R) _ :=
+-- Porting note: replaced `@[is_poly]` with `instance`.
+instance negIsPoly [Fact p.Prime] : IsPoly p fun R _ => @Neg.neg (𝕎 R) _ :=
   ⟨⟨fun n => rename Prod.snd (wittNeg p n), by
       intros; funext n
       rw [neg_coeff, aeval_eq_eval₂Hom, eval₂Hom_rename]
@@ -533,16 +351,16 @@ instance oneIsPoly [Fact p.Prime] : IsPoly p fun _ _ _ => 1 :=
 end ZeroOne
 
 /-- Addition of Witt vectors is a polynomial function. -/
-@[is_poly]
-theorem addIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
+-- Porting note: replaced `@[is_poly]` with `instance`.
+instance addIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· + ·) :=
   --  porting note: the proof was
   --  `⟨⟨wittAdd p, by intros; dsimp only [WittVector.hasAdd]; simp [eval]⟩⟩`
   ⟨⟨wittAdd p, by intros; ext; exact add_coeff _ _ _⟩⟩
 #align witt_vector.add_is_poly₂ WittVector.addIsPoly₂
 
 /-- Multiplication of Witt vectors is a polynomial function. -/
-@[is_poly]
-theorem mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
+-- Porting note: replaced `@[is_poly]` with `instance`.
+instance mulIsPoly₂ [Fact p.Prime] : IsPoly₂ p fun _ _ => (· * ·) :=
   --  porting note: the proof was
   -- `⟨⟨wittMul p, by intros; dsimp only [WittVector.hasMul]; simp [eval]⟩⟩`
   ⟨⟨wittMul p, by intros; ext; exact mul_coeff _ _ _⟩⟩
@@ -568,23 +386,24 @@ namespace IsPoly₂
 instance [Fact p.Prime] : Inhabited (IsPoly₂ p (fun _ _ => (· + ·))) :=
   ⟨addIsPoly₂⟩
 
+-- Porting note: maybe just drop this now that it works by `inferInstance`
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the first argument is polynomial. -/
-theorem compLeft {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
+theorem compLeft {g f} [IsPoly₂ p g] [IsPoly p f] :
     IsPoly₂ p fun _R _Rcr x y => g (f x) y :=
-  hg.comp hf (WittVector.idIsPoly _)
+  inferInstance
 #align witt_vector.is_poly₂.comp_left WittVector.IsPoly₂.compLeft
 
+-- Porting note: maybe just drop this now that it works by `inferInstance`
 /-- The composition of a binary polynomial function
  with a unary polynomial function in the second argument is polynomial. -/
-theorem compRight {g f} (hg : IsPoly₂ p g) (hf : IsPoly p f) :
+theorem compRight {g f} [IsPoly₂ p g] [IsPoly p f] :
     IsPoly₂ p fun _R _Rcr x y => g x (f y) :=
-  hg.comp (WittVector.idIsPoly p) hf
+  inferInstance
 #align witt_vector.is_poly₂.comp_right WittVector.IsPoly₂.compRight
 
 theorem ext [Fact p.Prime] {f g} (hf : IsPoly₂ p f) (hg : IsPoly₂ p g)
-    (h :
-      ∀ (R : Type u) [_Rcr : CommRing R] (x y : 𝕎 R) (n : ℕ),
+    (h : ∀ (R : Type u) [_Rcr : CommRing R] (x y : 𝕎 R) (n : ℕ),
         ghostComponent n (f x y) = ghostComponent n (g x y)) :
     ∀ (R) [_Rcr : CommRing R] (x y : 𝕎 R), f x y = g x y := by
   obtain ⟨φ, hf⟩ := hf
@@ -638,6 +457,89 @@ attribute [ghost_simps] AlgHom.map_zero AlgHom.map_one AlgHom.map_add AlgHom.map
   Nat.succ_eq_add_one if_true eq_self_iff_true if_false forall_true_iff forall₂_true_iff
   forall₃_true_iff
 
-end  -- porting note: ends the `noncomputable section`?
+end
+
+namespace Tactic
+open Lean Parser.Tactic Elab.Tactic
+
+/-- A macro for a common simplification when rewriting with ghost component equations. -/
+syntax (name := ghostSimp) "ghost_simp" (simpArgs)? : tactic
+
+macro_rules
+  | `(tactic| ghost_simp $[[$simpArgs,*]]?) => do
+    let args := simpArgs.map (·.getElems) |>.getD #[]
+    `(tactic| simp only [← sub_eq_add_neg, ghost_simps, $args,*])
+
+
+/-- `ghost_calc` is a tactic for proving identities between polynomial functions.
+Typically, when faced with a goal like
+```lean
+∀ (x y : 𝕎 R), verschiebung (x * frobenius y) = verschiebung x * y
+```
+you can
+1. call `ghost_calc`
+2. do a small amount of manual work -- maybe nothing, maybe `rintro`, etc
+3. call `ghost_simp`
+
+and this will close the goal.
+
+`ghost_calc` cannot detect whether you are dealing with unary or binary polynomial functions.
+You must give it arguments to determine this.
+If you are proving a universally quantified goal like the above,
+call `ghost_calc _ _`.
+If the variables are introduced already, call `ghost_calc x y`.
+In the unary case, use `ghost_calc _` or `ghost_calc x`.
+
+`ghost_calc` is a light wrapper around type class inference.
+All it does is apply the appropriate extensionality lemma and try to infer the resulting goals.
+This is subtle and Lean's elaborator doesn't like it because of the HO unification involved,
+so it is easier (and prettier) to put it in a tactic script.
+-/
+syntax (name := ghostCalc) "ghost_calc" (ppSpace colGt term:max)* : tactic
+
+private def runIntro (ref : Syntax) (n : Name) : TacticM FVarId := do
+  let fvarId ← liftMetaTacticAux fun g => do
+    let (fv, g') ← g.intro n
+    return (fv, [g'])
+  withMainContext do
+    Elab.Term.addLocalVarInfo ref (mkFVar fvarId)
+  return fvarId
+
+private def getLocalOrIntro (t : Term) : TacticM FVarId := do
+  match t with
+    | `(_) => runIntro t `_
+    | `($id:ident) => getFVarId id <|> runIntro id id.getId
+    | _ => Elab.throwUnsupportedSyntax
+
+elab_rules : tactic | `(tactic| ghost_calc $[$ids']*) => do
+  let ids ← ids'.mapM getLocalOrIntro
+  withMainContext do
+  let idsS ← ids.mapM (fun id => Elab.Term.exprToSyntax (.fvar id))
+  let some (α, lhs, rhs) := (← getMainTarget'').eq?
+    | throwError "ghost_calc expecting target to be an equality"
+  let (``WittVector, #[_, R]) := α.getAppFnArgs
+    | throwError "ghost_calc expecting target to be an equality of `WittVector`s"
+  let instR ← Meta.synthInstance (← Meta.mkAppM ``CommRing #[R])
+  unless instR.isFVar do
+    throwError "{← Meta.inferType instR} instance is not local"
+  let f ← Meta.mkLambdaFVars (#[R, instR] ++ ids.map .fvar) lhs
+  let g ← Meta.mkLambdaFVars (#[R, instR] ++ ids.map .fvar) rhs
+  let fS ← Elab.Term.exprToSyntax f
+  let gS ← Elab.Term.exprToSyntax g
+  match idsS with
+    | #[x] => evalTactic (← `(tactic| refine IsPoly.ext (f := $fS) (g := $gS) ?_ ?_ ?_ _ $x))
+    | #[x, y] => evalTactic (← `(tactic| refine IsPoly₂.ext (f := $fS) (g := $gS) ?_ ?_ ?_ _ $x $y))
+    | _ => throwError "ghost_calc takes either one or two arguments"
+  let nm ← withMainContext <|
+    if let .fvar fvarId := (R : Expr) then
+      fvarId.getUserName
+    else
+      Meta.getUnusedUserName `R
+  evalTactic <| ← `(tactic| iterate 2 infer_instance)
+  let R := mkIdent nm
+  evalTactic <| ← `(tactic| clear! $R)
+  evalTactic <| ← `(tactic| intro $(mkIdent nm):ident $(mkIdent (.str nm "_inst")):ident $ids'*)
+
+end Tactic
 
 end WittVector

168ad7fc

chore: convert lambda in docs to fun (#5045)

Found with git grep -n "λ [a-zA-Z_ ]*,"

1164cf04

Diff

@@ -339,7 +339,7 @@ theorem IsPoly.comp₂ {g f} (hg : IsPoly p g) (hf : IsPoly₂ p f) :
   simp only [peval, aeval_bind₁, Function.comp, hg, hf]
 #align witt_vector.is_poly.comp₂ WittVector.IsPoly.comp₂
 
-/-- The diagonal `λ x, f x x` of a polynomial function `f` is polynomial. -/
+/-- The diagonal `fun x ↦ f x x` of a polynomial function `f` is polynomial. -/
 theorem IsPoly₂.diag {f} (hf : IsPoly₂ p f) : IsPoly p fun R _Rcr x => f x x := by
   obtain ⟨φ, hf⟩ := hf
   refine' ⟨⟨fun n => bind₁ (uncurry ![X, X]) (φ n), _⟩⟩

168ad7fc

chore: tidy various files (#4997)

95de1dee

Diff

@@ -15,17 +15,17 @@ import Mathlib.RingTheory.WittVector.WittAttributes
 /-!
 # The `is_poly` predicate
 
-`witt_vector.is_poly` is a (type-valued) predicate on functions `f : Π R, 𝕎 R → 𝕎 R`.
-It asserts that there is a family of polynomials `φ : ℕ → mv_polynomial ℕ ℤ`,
+`WittVector.IsPoly` is a (type-valued) predicate on functions `f : Π R, 𝕎 R → 𝕎 R`.
+It asserts that there is a family of polynomials `φ : ℕ → MvPolynomial ℕ ℤ`,
 such that the `n`th coefficient of `f x` is equal to `φ n` evaluated on the coefficients of `x`.
 Many operations on Witt vectors satisfy this predicate (or an analogue for higher arity functions).
 We say that such a function `f` is a *polynomial function*.
 
-The power of satisfying this predicate comes from `is_poly.ext`.
+The power of satisfying this predicate comes from `WittVector.IsPoly.ext`.
 It shows that if `φ` and `ψ` witness that `f` and `g` are polynomial functions,
 then `f = g` not merely when `φ = ψ`, but in fact it suffices to prove
 ```
-∀ n, bind₁ φ (witt_polynomial p _ n) = bind₁ ψ (witt_polynomial p _ n)
+∀ n, bind₁ φ (wittPolynomial p _ n) = bind₁ ψ (wittPolynomial p _ n)
 ```
 (in other words, when evaluating the Witt polynomials on `φ` and `ψ`, we get the same values)
 which will then imply `φ = ψ` and hence `f = g`.
@@ -34,28 +34,28 @@ Even though this sufficient condition looks somewhat intimidating,
 it is rather pleasant to check in practice;
 more so than direct checking of `φ = ψ`.
 
-In practice, we apply this technique to show that the composition of `witt_vector.frobenius`
-and `witt_vector.verschiebung` is equal to multiplication by `p`.
+In practice, we apply this technique to show that the composition of `WittVector.frobenius`
+and `WittVector.verschiebung` is equal to multiplication by `p`.
 
 ## Main declarations
 
-* `witt_vector.is_poly`, `witt_vector.is_poly₂`:
+* `WittVector.IsPoly`, `WittVector.IsPoly₂`:
   two predicates that assert that a unary/binary function on Witt vectors
   is polynomial in the coefficients of the input values.
-* `witt_vector.is_poly.ext`, `witt_vector.is_poly₂.ext`:
+* `WittVector.IsPoly.ext`, `WittVector.IsPoly₂.ext`:
   two polynomial functions are equal if their families of polynomials are equal
   after evaluating the Witt polynomials on them.
-* `witt_vector.is_poly.comp` (+ many variants) show that unary/binary compositions
+* `WittVector.IsPoly.comp` (+ many variants) show that unary/binary compositions
   of polynomial functions are polynomial.
-* `witt_vector.id_is_poly`, `witt_vector.neg_is_poly`,
-  `witt_vector.add_is_poly₂`, `witt_vector.mul_is_poly₂`:
+* `WittVector.idIsPoly`, `WittVector.negIsPoly`,
+  `WittVector.addIsPoly₂`, `WittVector.mulIsPoly₂`:
   several well-known operations are polynomial functions
   (for Verschiebung, Frobenius, and multiplication by `p`, see their respective files).
 
 ## On higher arity analogues
 
-Ideally, there should be a predicate `is_polyₙ` for functions of higher arity,
-together with `is_polyₙ.comp` that shows how such functions compose.
+Ideally, there should be a predicate `IsPolyₙ` for functions of higher arity,
+together with `IsPolyₙ.comp` that shows how such functions compose.
 Since mathlib does not have a library on composition of higher arity functions,
 we have only implemented the unary and binary variants so far.
 Nullary functions (a.k.a. constants) are treated
@@ -67,15 +67,15 @@ There are important metaprograms defined in this file:
 the tactics `ghost_simp` and `ghost_calc` and the attributes `@[is_poly]` and `@[ghost_simps]`.
 These are used in combination to discharge proofs of identities between polynomial functions.
 
-Any atomic proof of `is_poly` or `is_poly₂` (i.e. not taking additional `is_poly` arguments)
+Any atomic proof of `IsPoly` or `IsPoly₂` (i.e. not taking additional `IsPoly` arguments)
 should be tagged as `@[is_poly]`.
 
 Any lemma doing "ring equation rewriting" with polynomial functions should be tagged
 `@[ghost_simps]`, e.g.
 ```lean
 @[ghost_simps]
-lemma bind₁_frobenius_poly_witt_polynomial (n : ℕ) :
-  bind₁ (frobenius_poly p) (witt_polynomial p ℤ n) = (witt_polynomial p ℤ (n+1))
+lemma bind₁_frobenius_poly_wittPolynomial (n : ℕ) :
+  bind₁ (frobenius_poly p) (wittPolynomial p ℤ n) = (wittPolynomial p ℤ (n+1))
 ```
 
 Proofs of identities between polynomial functions will often follow the pattern
@@ -166,7 +166,6 @@ universe u
 
 variable {p : ℕ} {R S : Type u} {σ idx : Type _} [CommRing R] [CommRing S]
 
--- mathport name: expr𝕎
 local notation "𝕎" => WittVector p
 
 -- type as `\bbW`
@@ -179,7 +178,7 @@ variable (p)
 noncomputable section
 
 /-!
-### The `is_poly` predicate
+### The `IsPoly` predicate
 -/
 
 
@@ -212,12 +211,12 @@ A function `f : Π R, 𝕎 R → 𝕎 R` that maps Witt vectors to Witt vectors
 is said to be *polynomial* if there is a family of polynomials `φₙ` over `ℤ` such that the `n`th
 coefficient of `f x` is given by evaluating `φₙ` at the coefficients of `x`.
 
-See also `witt_vector.is_poly₂` for the binary variant.
+See also `WittVector.IsPoly₂` for the binary variant.
 
-The `ghost_calc` tactic treats `is_poly` as a type class,
+The `ghost_calc` tactic treats `IsPoly` as a type class,
 and the `@[is_poly]` attribute derives certain specialized composition instances
-for declarations of type `is_poly f`.
-For the most part, users are not expected to treat `is_poly` as a class.
+for declarations of type `IsPoly f`.
+For the most part, users are not expected to treat `IsPoly` as a class.
 -/
 class IsPoly (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R) : Prop where mk' ::
   poly :
@@ -285,12 +284,12 @@ end IsPoly
 is said to be *polynomial* if there is a family of polynomials `φₙ` over `ℤ` such that the `n`th
 coefficient of `f x y` is given by evaluating `φₙ` at the coefficients of `x` and `y`.
 
-See also `witt_vector.is_poly` for the unary variant.
+See also `WittVector.IsPoly` for the unary variant.
 
-The `ghost_calc` tactic treats `is_poly₂` as a type class,
+The `ghost_calc` tactic treats `IsPoly₂` as a type class,
 and the `@[is_poly]` attribute derives certain specialized composition instances
-for declarations of type `is_poly₂ f`.
-For the most part, users are not expected to treat `is_poly₂` as a class.
+for declarations of type `IsPoly₂ f`.
+For the most part, users are not expected to treat `IsPoly₂` as a class.
 -/
 class IsPoly₂ (f : ∀ ⦃R⦄ [CommRing R], WittVector p R → 𝕎 R → 𝕎 R) : Prop where mk' ::
   poly :
@@ -365,10 +364,10 @@ namespace Tactic
 ### The `@[is_poly]` attribute
 
 This attribute is used to derive specialized composition instances
-for `is_poly` and `is_poly₂` declarations.
+for `IsPoly` and `IsPoly₂` declarations.
 -/
 
-/-- If `n` is the name of a lemma with opened type `∀ vars, is_poly p _`,
+/-- If `n` is the name of a lemma with opened type `∀ vars, IsPoly p _`,
 `mk_poly_comp_lemmas n vars p` adds composition instances to the environment
 `n.comp_i` and `n.comp₂_i`.
 -/
@@ -393,7 +392,7 @@ unsafe def mk_poly_comp_lemmas (n : Name) (vars : List expr) (p : expr) : tactic
   set_attribute `instance nm
 #align witt_vector.tactic.mk_poly_comp_lemmas witt_vector.tactic.mk_poly_comp_lemmas
 
-/-- If `n` is the name of a lemma with opened type `∀ vars, is_poly₂ p _`,
+/-- If `n` is the name of a lemma with opened type `∀ vars, IsPoly₂ p _`,
 `mk_poly₂_comp_lemmas n vars p` adds composition instances to the environment
 `n.comp₂_i` and `n.comp_diag`.
 -/
@@ -429,43 +428,43 @@ unsafe def mk_comp_lemmas (n : Name) : tactic Unit := do
   match tp with
     | q(IsPoly $(p) _) => mk_poly_comp_lemmas n vars p
     | q(IsPoly₂ $(p) _) => mk_poly₂_comp_lemmas n vars p
-    | _ => fail "@[is_poly] should only be applied to terms of type `is_poly _ _` or `is_poly₂ _ _`"
+    | _ => fail "@[is_poly] should only be applied to terms of type `IsPoly _ _` or `IsPoly₂ _ _`"
 #align witt_vector.tactic.mk_comp_lemmas witt_vector.tactic.mk_comp_lemmas
 
-/-- `@[is_poly]` is applied to lemmas of the form `is_poly f φ` or `is_poly₂ f φ`.
-These lemmas should *not* be tagged as instances, and only atomic `is_poly` defs should be tagged:
-composition lemmas should not. Roughly speaking, lemmas that take `is_poly` proofs as arguments
+/-- `@[is_poly]` is applied to lemmas of the form `IsPoly f φ` or `IsPoly₂ f φ`.
+These lemmas should *not* be tagged as instances, and only atomic `IsPoly` defs should be tagged:
+composition lemmas should not. Roughly speaking, lemmas that take `IsPoly` proofs as arguments
 should not be tagged.
 
 Type class inference struggles with function composition, and the higher order unification problems
-involved in inferring `is_poly` proofs are complex. The standard style writing these proofs by hand
+involved in inferring `IsPoly` proofs are complex. The standard style writing these proofs by hand
 doesn't work very well. Instead, we construct the type class hierarchy "under the hood", with
 limited forms of composition.
 
 Applying `@[is_poly]` to a lemma creates a number of instances. Roughly, if the tagged lemma is a
-proof of `is_poly f φ`, the instances added have the form
+proof of `IsPoly f φ`, the instances added have the form
 ```lean
-∀ g ψ, [is_poly g ψ] → is_poly (f ∘ g) _
+∀ g ψ, [IsPoly g ψ] → IsPoly (f ∘ g) _
 ```
 Since `f` is fixed in this instance, it restricts the HO unification needed when the instance is
-applied. Composition lemmas relating `is_poly` with `is_poly₂` are also added.
-`id_is_poly` is an atomic instance.
+applied. Composition lemmas relating `IsPoly` with `IsPoly₂` are also added.
+`idIsPoly` is an atomic instance.
 
 The user-written lemmas are not instances. Users should be able to assemble `is_poly` proofs by hand
 "as normal" if the tactic fails.
 -/
 @[user_attribute]
-unsafe def is_poly_attr : user_attribute where
-  Name := `is_poly
+unsafe def isPolyAttr : user_attribute where
+  Name := `IsPoly
   descr := "Lemmas with this attribute describe the polynomial structure of functions"
   after_set := some fun n _ _ => mk_comp_lemmas n
-#align witt_vector.tactic.is_poly_attr witt_vector.tactic.is_poly_attr
+#align witt_vector.tactic.is_poly_attr WittVector.Tactic.isPolyAttr
 
 end Tactic
 -/
 
 /-!
-### `is_poly` instances
+### `IsPoly` instances
 
 These are not declared as instances at the top level,
 but the `@[is_poly]` attribute adds instances based on each one.
@@ -508,8 +507,7 @@ theorem bind₁_onePoly_wittPolynomial [hp : Fact p.Prime] (n : ℕ) :
     bind₁ onePoly (wittPolynomial p ℤ n) = 1 := by
   ext  -- porting note: `ext` was not in the mathport output.
   rw [wittPolynomial_eq_sum_c_mul_x_pow, AlgHom.map_sum, Finset.sum_eq_single 0]
-  ·
-    simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
+  · simp only [onePoly, one_pow, one_mul, AlgHom.map_pow, C_1, pow_zero, bind₁_X_right, if_true,
       eq_self_iff_true]
   · intro i _hi hi0
     simp only [onePoly, if_neg hi0, zero_pow (pow_pos hp.1.pos _), MulZeroClass.mul_zero,
@@ -555,7 +553,7 @@ theorem IsPoly.map [Fact p.Prime] {f} (hf : IsPoly p f) (g : R →+* S) (x : 
     map g (f x) = f (map g x) := by
   -- this could be turned into a tactic “macro” (taking `hf` as parameter)
   -- so that applications do not have to worry about the universe issue
-  -- see `is_poly₂.map` for a slightly more general proof strategy
+  -- see `IsPoly₂.map` for a slightly more general proof strategy
   obtain ⟨φ, hf⟩ := hf
   ext n
   simp only [map_coeff, hf, map_aeval]

168ad7fc

feat: port RingTheory.WittVector.IsPoly (#4851)

This file contains a couple of tactics. I ported everything that is not a tactic and added an "attributes" file.

My plan is to try to develop the tactics while porting a file that actually uses them.

5d808684

`ring_theory.witt_vector.is_poly` ⟷ `Mathlib.RingTheory.WittVector.IsPoly`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

PR contents

Lean PRs involved in this bump

leanprover/lean4#2778

leanprover/lean4#2722

leanprover/lean4#2783

Dependencies 10 + 674

ring_theory.witt_vector.is_poly ⟷ Mathlib.RingTheory.WittVector.IsPoly

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

PR contents

Lean PRs involved in this bump

leanprover/lean4#2778

leanprover/lean4#2722

leanprover/lean4#2783

Dependencies 10 + 674

`ring_theory.witt_vector.is_poly` ⟷ `Mathlib.RingTheory.WittVector.IsPoly`