data.fun_like.embedding | Mathlib porting status

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

c4658a64

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

448144f7

bump to nightly-2024-01-19-06

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

33b57512

Diff

@@ -139,7 +139,7 @@ instead of linearly increasing the work per `my_embedding`-related declaration.
 /-- The class `embedding_like F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
-class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends FunLike F α fun _ => β where
+class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends DFunLike F α fun _ => β where
   injective' : ∀ f : F, @Function.Injective α β (coe f)
 #align embedding_like EmbeddingLike
 -/

448144f7

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,7 +3,7 @@ Copyright (c) 2021 Anne Baanen. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Anne Baanen
 -/
-import Mathbin.Data.FunLike.Basic
+import Data.FunLike.Basic
 
 #align_import data.fun_like.embedding from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"

448144f7

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,14 +2,11 @@
 Copyright (c) 2021 Anne Baanen. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Anne Baanen
-
-! This file was ported from Lean 3 source module data.fun_like.embedding
-! leanprover-community/mathlib commit 448144f7ae193a8990cb7473c9e9a01990f64ac7
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Data.FunLike.Basic
 
+#align_import data.fun_like.embedding from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # Typeclass for a type `F` with an injective map to `A ↪ B`

448144f7

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -138,35 +138,39 @@ instead of linearly increasing the work per `my_embedding`-related declaration.
 -/
 
 
+#print EmbeddingLike /-
 /-- The class `embedding_like F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
 class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends FunLike F α fun _ => β where
   injective' : ∀ f : F, @Function.Injective α β (coe f)
 #align embedding_like EmbeddingLike
+-/
 
 namespace EmbeddingLike
 
 variable {F α β γ : Sort _} [i : EmbeddingLike F α β]
 
-include i
-
+#print EmbeddingLike.injective /-
 protected theorem injective (f : F) : Function.Injective f :=
   injective' f
 #align embedding_like.injective EmbeddingLike.injective
+-/
 
+#print EmbeddingLike.apply_eq_iff_eq /-
 @[simp]
 theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
   (EmbeddingLike.injective f).eq_iff
 #align embedding_like.apply_eq_iff_eq EmbeddingLike.apply_eq_iff_eq
+-/
 
-omit i
-
+#print EmbeddingLike.comp_injective /-
 @[simp]
 theorem comp_injective {F : Sort _} [EmbeddingLike F β γ] (f : α → β) (e : F) :
     Function.Injective (e ∘ f) ↔ Function.Injective f :=
   (EmbeddingLike.injective e).of_comp_iff f
 #align embedding_like.comp_injective EmbeddingLike.comp_injective
+-/
 
 end EmbeddingLike

448144f7

bump to nightly-2023-05-28-06

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

ba5d8b97

Diff

@@ -138,12 +138,6 @@ instead of linearly increasing the work per `my_embedding`-related declaration.
 -/
 
 
-/- warning: embedding_like -> EmbeddingLike is a dubious translation:
-lean 3 declaration is
-  Sort.{u1} -> (outParam.{succ u2} Sort.{u2}) -> (outParam.{succ u3} Sort.{u3}) -> Sort.{max 1 (imax u1 u2 u3)}
-but is expected to have type
-  Sort.{u1} -> (outParam.{succ u2} Sort.{u2}) -> (outParam.{succ u3} Sort.{u3}) -> Sort.{max (max (max 1 u1) u2) u3}
-Case conversion may be inaccurate. Consider using '#align embedding_like EmbeddingLikeₓ'. -/
 /-- The class `embedding_like F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
@@ -157,22 +151,10 @@ variable {F α β γ : Sort _} [i : EmbeddingLike F α β]
 
 include i
 
-/- warning: embedding_like.injective -> EmbeddingLike.injective is a dubious translation:
-lean 3 declaration is
-  forall {F : Sort.{u1}} {α : Sort.{u2}} {β : Sort.{u3}} [i : EmbeddingLike.{u1, u2, u3} F α β] (f : F), Function.Injective.{u2, u3} α β (coeFn.{u1, imax u2 u3} F (fun (_x : F) => α -> β) (FunLike.hasCoeToFun.{u1, u2, u3} F α (fun (_x : α) => β) (EmbeddingLike.toFunLike.{u1, u2, u3} F α β i)) f)
-but is expected to have type
-  forall {F : Sort.{u1}} {α : Sort.{u3}} {β : Sort.{u2}} [i : EmbeddingLike.{u1, u3, u2} F α β] (f : F), Function.Injective.{u3, u2} α β (FunLike.coe.{u1, u3, u2} F α (fun (_x : α) => (fun (x._@.Mathlib.Data.FunLike.Embedding._hyg.19 : α) => β) _x) (EmbeddingLike.toFunLike.{u1, u3, u2} F α β i) f)
-Case conversion may be inaccurate. Consider using '#align embedding_like.injective EmbeddingLike.injectiveₓ'. -/
 protected theorem injective (f : F) : Function.Injective f :=
   injective' f
 #align embedding_like.injective EmbeddingLike.injective
 
-/- warning: embedding_like.apply_eq_iff_eq -> EmbeddingLike.apply_eq_iff_eq is a dubious translation:
-lean 3 declaration is
-  forall {F : Sort.{u1}} {α : Sort.{u2}} {β : Sort.{u3}} [i : EmbeddingLike.{u1, u2, u3} F α β] (f : F) {x : α} {y : α}, Iff (Eq.{u3} β (coeFn.{u1, imax u2 u3} F (fun (_x : F) => α -> β) (FunLike.hasCoeToFun.{u1, u2, u3} F α (fun (_x : α) => β) (EmbeddingLike.toFunLike.{u1, u2, u3} F α β i)) f x) (coeFn.{u1, imax u2 u3} F (fun (_x : F) => α -> β) (FunLike.hasCoeToFun.{u1, u2, u3} F α (fun (_x : α) => β) (EmbeddingLike.toFunLike.{u1, u2, u3} F α β i)) f y)) (Eq.{u2} α x y)
-but is expected to have type
-  forall {F : Sort.{u2}} {α : Sort.{u1}} {β : Sort.{u3}} [i : EmbeddingLike.{u2, u1, u3} F α β] (f : F) {x : α} {y : α}, Iff (Eq.{u3} ((fun (x._@.Mathlib.Data.FunLike.Embedding._hyg.19 : α) => β) x) (FunLike.coe.{u2, u1, u3} F α (fun (_x : α) => (fun (x._@.Mathlib.Data.FunLike.Embedding._hyg.19 : α) => β) _x) (EmbeddingLike.toFunLike.{u2, u1, u3} F α β i) f x) (FunLike.coe.{u2, u1, u3} F α (fun (_x : α) => (fun (x._@.Mathlib.Data.FunLike.Embedding._hyg.19 : α) => β) _x) (EmbeddingLike.toFunLike.{u2, u1, u3} F α β i) f y)) (Eq.{u1} α x y)
-Case conversion may be inaccurate. Consider using '#align embedding_like.apply_eq_iff_eq EmbeddingLike.apply_eq_iff_eqₓ'. -/
 @[simp]
 theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
   (EmbeddingLike.injective f).eq_iff
@@ -180,12 +162,6 @@ theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
 
 omit i
 
-/- warning: embedding_like.comp_injective -> EmbeddingLike.comp_injective is a dubious translation:
-lean 3 declaration is
-  forall {α : Sort.{u1}} {β : Sort.{u2}} {γ : Sort.{u3}} {F : Sort.{u4}} [_inst_1 : EmbeddingLike.{u4, u2, u3} F β γ] (f : α -> β) (e : F), Iff (Function.Injective.{u1, u3} α γ (Function.comp.{u1, u2, u3} α β γ (coeFn.{u4, imax u2 u3} F (fun (_x : F) => β -> γ) (FunLike.hasCoeToFun.{u4, u2, u3} F β (fun (_x : β) => γ) (EmbeddingLike.toFunLike.{u4, u2, u3} F β γ _inst_1)) e) f)) (Function.Injective.{u1, u2} α β f)
-but is expected to have type
-  forall {α : Sort.{u1}} {β : Sort.{u3}} {γ : Sort.{u2}} {F : Sort.{u4}} [_inst_1 : EmbeddingLike.{u4, u3, u2} F β γ] (f : α -> β) (e : F), Iff (Function.Injective.{u1, u2} α γ (Function.comp.{u1, u3, u2} α β γ (FunLike.coe.{u4, u3, u2} F β (fun (_x : β) => (fun (x._@.Mathlib.Data.FunLike.Embedding._hyg.19 : β) => γ) _x) (EmbeddingLike.toFunLike.{u4, u3, u2} F β γ _inst_1) e) f)) (Function.Injective.{u1, u3} α β f)
-Case conversion may be inaccurate. Consider using '#align embedding_like.comp_injective EmbeddingLike.comp_injectiveₓ'. -/
 @[simp]
 theorem comp_injective {F : Sort _} [EmbeddingLike F β γ] (f : α → β) (e : F) :
     Function.Injective (e ∘ f) ↔ Function.Injective f :=

448144f7

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

c4658a64

chore(Data/Funlike): update examples and replace Lean 3 syntax (#11409)

Fully update the module docstrings (in particular, the examples given therein) after #8386.

This includes switching to where syntax, but also replacing Lean 3 syntax, replacing => by "\mapsto" while at it and indenting code per the style guide. As such, it's also a follow-up to #11301.

Co-authored-by: @Vierkantor

Co-authored-by: Vierkantor <vierkantor@vierkantor.com>

9db65796

Diff

@@ -19,28 +19,27 @@ A typical type of embeddings should be declared as:
 structure MyEmbedding (A B : Type*) [MyClass A] [MyClass B] :=
   (toFun : A → B)
   (injective' : Function.Injective toFun)
-  (map_op' : ∀ {x y : A}, toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
+  (map_op' : ∀ (x y : A), toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
 
 namespace MyEmbedding
 
 variable (A B : Type*) [MyClass A] [MyClass B]
 
--- This instance is optional if you follow the "Embedding class" design below:
-instance : EmbeddingLike (MyEmbedding A B) A B :=
-  { coe := MyEmbedding.toFun,
-    coe_injective' := λ f g h, by cases f; cases g; congr',
-    injective' := MyEmbedding.injective' }
+instance : FunLike (MyEmbedding A B) A B where
+  coe := MyEmbedding.toFun
+  coe_injective' := fun f g h ↦ by cases f; cases g; congr
 
-/-- Helper instance for when there's too many metavariables to `EmbeddingLike.coe` directly. -/
-instance : CoeFun (MyEmbedding A B) (λ _, A → B) := ⟨MyEmbedding.toFun⟩
+-- This instance is optional if you follow the "Embedding class" design below:
+instance : EmbeddingLike (MyEmbedding A B) A B where
+  injective' := MyEmbedding.injective'
 
 @[ext] theorem ext {f g : MyEmbedding A B} (h : ∀ x, f x = g x) : f = g := DFunLike.ext f g h
 
 /-- Copy of a `MyEmbedding` with a new `toFun` equal to the old one. Useful to fix definitional
 equalities. -/
 protected def copy (f : MyEmbedding A B) (f' : A → B) (h : f' = ⇑f) : MyEmbedding A B :=
-  { toFun := f',
-    injective' := h.symm ▸ f.injective',
+  { toFun := f'
+    injective' := h.symm ▸ f.injective'
     map_op' := h.symm ▸ f.map_op' }
 
 end MyEmbedding
@@ -57,28 +56,29 @@ the axioms of your new type of morphisms.
 Continuing the example above:
 
 ```
-section
-
 /-- `MyEmbeddingClass F A B` states that `F` is a type of `MyClass.op`-preserving embeddings.
 You should extend this class when you extend `MyEmbedding`. -/
 class MyEmbeddingClass (F : Type*) (A B : outParam <| Type*) [MyClass A] [MyClass B]
-  extends EmbeddingLike F A B :=
-(map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))
+    [FunLike F A B]
+    extends EmbeddingLike F A B :=
+  (map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))
 
-end
+@[simp]
+lemma map_op {F A B : Type*} [MyClass A] [MyClass B] [FunLike F A B] [MyEmbeddingClass F A B]
+    (f : F) (x y : A) :
+    f (MyClass.op x y) = MyClass.op (f x) (f y) :=
+  MyEmbeddingClass.map_op _ _ _
+
+namespace MyEmbedding
 
-@[simp] lemma map_op {F A B : Type*} [MyClass A] [MyClass B] [MyEmbeddingClass F A B]
-  (f : F) (x y : A) : f (MyClass.op x y) = MyClass.op (f x) (f y) :=
-MyEmbeddingClass.map_op
+variable {A B : Type*} [MyClass A] [MyClass B]
 
 -- You can replace `MyEmbedding.EmbeddingLike` with the below instance:
-instance : MyEmbeddingClass (MyEmbedding A B) A B :=
-  { coe := MyEmbedding.toFun,
-    coe_injective' := λ f g h, by cases f; cases g; congr',
-    injective' := MyEmbedding.injective',
-    map_op := MyEmbedding.map_op' }
+instance : MyEmbeddingClass (MyEmbedding A B) A B where
+  injective' := MyEmbedding.injective'
+  map_op := MyEmbedding.map_op'
 
--- [Insert `CoeFun`, `ext` and `copy` here]
+end MyEmbedding
 ```
 
 The second step is to add instances of your new `MyEmbeddingClass` for all types extending
@@ -86,45 +86,44 @@ The second step is to add instances of your new `MyEmbeddingClass` for all types
 Typically, you can just declare a new class analogous to `MyEmbeddingClass`:
 
 ```
-structure CoolerEmbedding (A B : Type*) [CoolClass A] [CoolClass B]
-  extends MyEmbedding A B :=
-(map_cool' : toFun CoolClass.cool = CoolClass.cool)
-
-section
-set_option old_structure_cmd true
+structure CoolerEmbedding (A B : Type*) [CoolClass A] [CoolClass B] extends MyEmbedding A B :=
+  (map_cool' : toFun CoolClass.cool = CoolClass.cool)
 
 class CoolerEmbeddingClass (F : Type*) (A B : outParam <| Type*) [CoolClass A] [CoolClass B]
-  extends MyEmbeddingClass F A B :=
-(map_cool : ∀ (f : F), f CoolClass.cool = CoolClass.cool)
+    [FunLike F A B]
+    extends MyEmbeddingClass F A B :=
+  (map_cool : ∀ (f : F), f CoolClass.cool = CoolClass.cool)
 
-end
+@[simp]
+lemma map_cool {F A B : Type*} [CoolClass A] [CoolClass B]
+    [FunLike F A B] [CoolerEmbeddingClass F A B] (f : F) :
+    f CoolClass.cool = CoolClass.cool :=
+  CoolerEmbeddingClass.map_cool _
 
-@[simp] lemma map_cool {F A B : Type*} [CoolClass A] [CoolClass B] [CoolerEmbeddingClass F A B]
-  (f : F) : f CoolClass.cool = CoolClass.cool :=
-MyEmbeddingClass.map_op
+variable {A B : Type*} [CoolClass A] [CoolClass B]
 
--- You can also replace `MyEmbedding.EmbeddingLike` with the below instance:
-instance : CoolerEmbeddingClass (CoolerEmbedding A B) A B :=
-  { coe := CoolerEmbedding.toFun,
-    coe_injective' := λ f g h, by cases f; cases g; congr',
-    injective' := MyEmbedding.injective',
-    map_op := CoolerEmbedding.map_op',
-    map_cool := CoolerEmbedding.map_cool' }
+instance : FunLike (CoolerEmbedding A B) A B where
+  coe f := f.toFun
+  coe_injective' f g h := by cases f; cases g; congr; apply DFunLike.coe_injective; congr
 
--- [Insert `CoeFun`, `ext` and `copy` here]
+instance : CoolerEmbeddingClass (CoolerEmbedding A B) A B where
+  injective' f := f.injective'
+  map_op f := f.map_op'
+  map_cool f := f.map_cool'
+
+-- [Insert `ext` and `copy` here]
 ```
 
 Then any declaration taking a specific type of morphisms as parameter can instead take the
 class you just defined:
 ```
 -- Compare with: lemma do_something (f : MyEmbedding A B) : sorry := sorry
-lemma do_something {F : Type*} [MyEmbeddingClass F A B] (f : F) : sorry := sorry
+lemma do_something {F : Type*} [FunLike F A B] [MyEmbeddingClass F A B] (f : F) : sorry := sorry
 ```
 
 This means anything set up for `MyEmbedding`s will automatically work for `CoolerEmbeddingClass`es,
 and defining `CoolerEmbeddingClass` only takes a constant amount of effort,
 instead of linearly increasing the work per `MyEmbedding`-related declaration.
-
 -/

c4658a64

doc: replace variables, universes' syntax in doc comments (#11404)

It's deprecated in favour of variable; likely a leftover from the port. Also replace universes, which is invalid now.

e88fcb88

Diff

@@ -23,7 +23,7 @@ structure MyEmbedding (A B : Type*) [MyClass A] [MyClass B] :=
 
 namespace MyEmbedding
 
-variables (A B : Type*) [MyClass A] [MyClass B]
+variable (A B : Type*) [MyClass A] [MyClass B]
 
 -- This instance is optional if you follow the "Embedding class" design below:
 instance : EmbeddingLike (MyEmbedding A B) A B :=

c4658a64

refactor(Data/FunLike): use unbundled inheritance from FunLike (#8386)

The FunLike hierarchy is very big and gets scanned through each time we need a coercion (via the CoeFun instance). It looks like unbundled inheritance suits Lean 4 better here. The only class that still extends FunLike is EquivLike, since that has a custom coe_injective' field that is easier to implement. All other classes should take FunLike or EquivLike as a parameter.

Zulip thread

Important changes

Previously, morphism classes would be Type-valued and extend FunLike:

/-- `MyHomClass F A B` states that `F` is a type of `MyClass.op`-preserving morphisms.
You should extend this class when you extend `MyHom`. -/
class MyHomClass (F : Type*) (A B : outParam <| Type*) [MyClass A] [MyClass B]
  extends FunLike F A B :=
(map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))

After this PR, they should be Prop-valued and take FunLike as a parameter:

/-- `MyHomClass F A B` states that `F` is a type of `MyClass.op`-preserving morphisms.
You should extend this class when you extend `MyHom`. -/
class MyHomClass (F : Type*) (A B : outParam <| Type*) [MyClass A] [MyClass B]
  [FunLike F A B] : Prop :=
(map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))

(Note that A B stay marked as outParam even though they are not purely required to be so due to the FunLike parameter already filling them in. This is required to see through type synonyms, which is important in the category theory library. Also, I think keeping them as outParam is slightly faster.)

Similarly, MyEquivClass should take EquivLike as a parameter.

As a result, every mention of [MyHomClass F A B] should become [FunLike F A B] [MyHomClass F A B].

Remaining issues

Slower (failing) search

While overall this gives some great speedups, there are some cases that are noticeably slower. In particular, a failing application of a lemma such as map_mul is more expensive. This is due to suboptimal processing of arguments. For example:

variable [FunLike F M N] [Mul M] [Mul N] (f : F) (x : M) (y : M)

theorem map_mul [MulHomClass F M N] : f (x * y) = f x * f y

example [AddHomClass F A B] : f (x * y) = f x * f y := map_mul f _ _

Before this PR, applying map_mul f gives the goals [Mul ?M] [Mul ?N] [MulHomClass F ?M ?N]. Since M and N are out_params, [MulHomClass F ?M ?N] is synthesized first, supplies values for ?M and ?N and then the Mul M and Mul N instances can be found.

After this PR, the goals become [FunLike F ?M ?N] [Mul ?M] [Mul ?N] [MulHomClass F ?M ?N]. Now [FunLike F ?M ?N] is synthesized first, supplies values for ?M and ?N and then the Mul M and Mul N instances can be found, before trying MulHomClass F M N which fails. Since the Mul hierarchy is very big, this can be slow to fail, especially when there is no such Mul instance.

A long-term but harder to achieve solution would be to specify the order in which instance goals get solved. For example, we'd like to change the arguments to map_mul to look like [FunLike F M N] [Mul M] [Mul N] [highPriority <| MulHomClass F M N] because MulHomClass fails or succeeds much faster than the others.

As a consequence, the simpNF linter is much slower since by design it tries and fails to apply many map_ lemmas. The same issue occurs a few times in existing calls to simp [map_mul], where map_mul is tried "too soon" and fails. Thanks to the speedup of leanprover/lean4#2478 the impact is very limited, only in files that already were close to the timeout.

`simp` not firing sometimes

This affects map_smulₛₗ and related definitions. For simp lemmas Lean apparently uses a slightly different mechanism to find instances, so that rw can find every argument to map_smulₛₗ successfully but simp can't: leanprover/lean4#3701.

Missing instances due to unification failing

Especially in the category theory library, we might sometimes have a type A which is also accessible as a synonym (Bundled A hA).1. Instance synthesis doesn't always work if we have f : A →* B but x * y : (Bundled A hA).1 or vice versa. This seems to be mostly fixed by keeping A B as outParams in MulHomClass F A B. (Presumably because Lean will do a definitional check A =?= (Bundled A hA).1 instead of using the syntax in the discrimination tree.)

Workaround for issues

The timeouts can be worked around for now by specifying which map_mul we mean, either as map_mul f for some explicit f, or as e.g. MonoidHomClass.map_mul.

map_smulₛₗ not firing as simp lemma can be worked around by going back to the pre-FunLike situation and making LinearMap.map_smulₛₗ a simp lemma instead of the generic map_smulₛₗ. Writing simp [map_smulₛₗ _] also works.

Co-authored-by: Matthew Ballard <matt@mrb.email> Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Scott Morrison <scott@tqft.net> Co-authored-by: Anne Baanen <Vierkantor@users.noreply.github.com>

c6a73d4f

Diff

@@ -131,14 +131,14 @@ instead of linearly increasing the work per `MyEmbedding`-related declaration.
 /-- The class `EmbeddingLike F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
-class EmbeddingLike (F : Sort*) (α β : outParam (Sort*)) extends DFunLike F α fun _ ↦ β where
+class EmbeddingLike (F : Sort*) (α β : outParam (Sort*)) [FunLike F α β] : Prop where
   /-- The coercion to functions must produce injective functions. -/
-  injective' : ∀ f : F, Function.Injective (coe f)
+  injective' : ∀ f : F, Function.Injective (DFunLike.coe f)
 #align embedding_like EmbeddingLike
 
 namespace EmbeddingLike
 
-variable {F α β γ : Sort*} [i : EmbeddingLike F α β]
+variable {F α β γ : Sort*} [FunLike F α β] [i : EmbeddingLike F α β]
 
 protected theorem injective (f : F) : Function.Injective f :=
   injective' f
@@ -150,7 +150,7 @@ theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
 #align embedding_like.apply_eq_iff_eq EmbeddingLike.apply_eq_iff_eq
 
 @[simp]
-theorem comp_injective {F : Sort*} [EmbeddingLike F β γ] (f : α → β) (e : F) :
+theorem comp_injective {F : Sort*} [FunLike F β γ] [EmbeddingLike F β γ] (f : α → β) (e : F) :
     Function.Injective (e ∘ f) ↔ Function.Injective f :=
   (EmbeddingLike.injective e).of_comp_iff f
 #align embedding_like.comp_injective EmbeddingLike.comp_injective

c4658a64

chore(*): rename FunLike to DFunLike (#9785)

This prepares for the introduction of a non-dependent synonym of FunLike, which helps a lot with keeping #8386 readable.

This is entirely search-and-replace in 680197f combined with manual fixes in 4145626, e900597 and b8428f8. The commands that generated this change:

sed -i 's/\bFunLike\b/DFunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean
sed -i 's/\btoFunLike\b/toDFunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean
sed -i 's/import Mathlib.Data.DFunLike/import Mathlib.Data.FunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean
sed -i 's/\bHom_FunLike\b/Hom_DFunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean     
sed -i 's/\binstFunLike\b/instDFunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean
sed -i 's/\bfunLike\b/instDFunLike/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean
sed -i 's/\btoo many metavariables to apply `fun_like.has_coe_to_fun`/too many metavariables to apply `DFunLike.hasCoeToFun`/g' {Archive,Counterexamples,Mathlib,test}/**/*.lean

Co-authored-by: Anne Baanen <Vierkantor@users.noreply.github.com>

82656743

Diff

@@ -34,7 +34,7 @@ instance : EmbeddingLike (MyEmbedding A B) A B :=
 /-- Helper instance for when there's too many metavariables to `EmbeddingLike.coe` directly. -/
 instance : CoeFun (MyEmbedding A B) (λ _, A → B) := ⟨MyEmbedding.toFun⟩
 
-@[ext] theorem ext {f g : MyEmbedding A B} (h : ∀ x, f x = g x) : f = g := FunLike.ext f g h
+@[ext] theorem ext {f g : MyEmbedding A B} (h : ∀ x, f x = g x) : f = g := DFunLike.ext f g h
 
 /-- Copy of a `MyEmbedding` with a new `toFun` equal to the old one. Useful to fix definitional
 equalities. -/
@@ -131,7 +131,7 @@ instead of linearly increasing the work per `MyEmbedding`-related declaration.
 /-- The class `EmbeddingLike F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
-class EmbeddingLike (F : Sort*) (α β : outParam (Sort*)) extends FunLike F α fun _ ↦ β where
+class EmbeddingLike (F : Sort*) (α β : outParam (Sort*)) extends DFunLike F α fun _ ↦ β where
   /-- The coercion to functions must produce injective functions. -/
   injective' : ∀ f : F, Function.Injective (coe f)
 #align embedding_like EmbeddingLike

c4658a64

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

@@ -16,14 +16,14 @@ This typeclass is primarily for use by embeddings such as `RelEmbedding`.
 
 A typical type of embeddings should be declared as:
 ```
-structure MyEmbedding (A B : Type _) [MyClass A] [MyClass B] :=
+structure MyEmbedding (A B : Type*) [MyClass A] [MyClass B] :=
   (toFun : A → B)
   (injective' : Function.Injective toFun)
   (map_op' : ∀ {x y : A}, toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
 
 namespace MyEmbedding
 
-variables (A B : Type _) [MyClass A] [MyClass B]
+variables (A B : Type*) [MyClass A] [MyClass B]
 
 -- This instance is optional if you follow the "Embedding class" design below:
 instance : EmbeddingLike (MyEmbedding A B) A B :=
@@ -61,13 +61,13 @@ section
 
 /-- `MyEmbeddingClass F A B` states that `F` is a type of `MyClass.op`-preserving embeddings.
 You should extend this class when you extend `MyEmbedding`. -/
-class MyEmbeddingClass (F : Type _) (A B : outParam <| Type _) [MyClass A] [MyClass B]
+class MyEmbeddingClass (F : Type*) (A B : outParam <| Type*) [MyClass A] [MyClass B]
   extends EmbeddingLike F A B :=
 (map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))
 
 end
 
-@[simp] lemma map_op {F A B : Type _} [MyClass A] [MyClass B] [MyEmbeddingClass F A B]
+@[simp] lemma map_op {F A B : Type*} [MyClass A] [MyClass B] [MyEmbeddingClass F A B]
   (f : F) (x y : A) : f (MyClass.op x y) = MyClass.op (f x) (f y) :=
 MyEmbeddingClass.map_op
 
@@ -86,20 +86,20 @@ The second step is to add instances of your new `MyEmbeddingClass` for all types
 Typically, you can just declare a new class analogous to `MyEmbeddingClass`:
 
 ```
-structure CoolerEmbedding (A B : Type _) [CoolClass A] [CoolClass B]
+structure CoolerEmbedding (A B : Type*) [CoolClass A] [CoolClass B]
   extends MyEmbedding A B :=
 (map_cool' : toFun CoolClass.cool = CoolClass.cool)
 
 section
 set_option old_structure_cmd true
 
-class CoolerEmbeddingClass (F : Type _) (A B : outParam <| Type _) [CoolClass A] [CoolClass B]
+class CoolerEmbeddingClass (F : Type*) (A B : outParam <| Type*) [CoolClass A] [CoolClass B]
   extends MyEmbeddingClass F A B :=
 (map_cool : ∀ (f : F), f CoolClass.cool = CoolClass.cool)
 
 end
 
-@[simp] lemma map_cool {F A B : Type _} [CoolClass A] [CoolClass B] [CoolerEmbeddingClass F A B]
+@[simp] lemma map_cool {F A B : Type*} [CoolClass A] [CoolClass B] [CoolerEmbeddingClass F A B]
   (f : F) : f CoolClass.cool = CoolClass.cool :=
 MyEmbeddingClass.map_op
 
@@ -118,7 +118,7 @@ Then any declaration taking a specific type of morphisms as parameter can instea
 class you just defined:
 ```
 -- Compare with: lemma do_something (f : MyEmbedding A B) : sorry := sorry
-lemma do_something {F : Type _} [MyEmbeddingClass F A B] (f : F) : sorry := sorry
+lemma do_something {F : Type*} [MyEmbeddingClass F A B] (f : F) : sorry := sorry
 ```
 
 This means anything set up for `MyEmbedding`s will automatically work for `CoolerEmbeddingClass`es,
@@ -131,14 +131,14 @@ instead of linearly increasing the work per `MyEmbedding`-related declaration.
 /-- The class `EmbeddingLike F α β` expresses that terms of type `F` have an
 injective coercion to injective functions `α ↪ β`.
 -/
-class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends FunLike F α fun _ ↦ β where
+class EmbeddingLike (F : Sort*) (α β : outParam (Sort*)) extends FunLike F α fun _ ↦ β where
   /-- The coercion to functions must produce injective functions. -/
   injective' : ∀ f : F, Function.Injective (coe f)
 #align embedding_like EmbeddingLike
 
 namespace EmbeddingLike
 
-variable {F α β γ : Sort _} [i : EmbeddingLike F α β]
+variable {F α β γ : Sort*} [i : EmbeddingLike F α β]
 
 protected theorem injective (f : F) : Function.Injective f :=
   injective' f
@@ -150,7 +150,7 @@ theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
 #align embedding_like.apply_eq_iff_eq EmbeddingLike.apply_eq_iff_eq
 
 @[simp]
-theorem comp_injective {F : Sort _} [EmbeddingLike F β γ] (f : α → β) (e : F) :
+theorem comp_injective {F : Sort*} [EmbeddingLike F β γ] (f : α → β) (e : F) :
     Function.Injective (e ∘ f) ↔ Function.Injective f :=
   (EmbeddingLike.injective e).of_comp_iff f
 #align embedding_like.comp_injective EmbeddingLike.comp_injective

c4658a64

style: leave some variables implicit (#6021)

b19ab15a

Diff

@@ -133,7 +133,7 @@ injective coercion to injective functions `α ↪ β`.
 -/
 class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends FunLike F α fun _ ↦ β where
   /-- The coercion to functions must produce injective functions. -/
-  injective' : ∀ f : F, @Function.Injective α β (coe f)
+  injective' : ∀ f : F, Function.Injective (coe f)
 #align embedding_like EmbeddingLike
 
 namespace EmbeddingLike

c4658a64

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

@@ -2,14 +2,11 @@
 Copyright (c) 2021 Anne Baanen. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Anne Baanen
-
-! This file was ported from Lean 3 source module data.fun_like.embedding
-! leanprover-community/mathlib commit c4658a649d216f57e99621708b09dcb3dcccbd23
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Data.FunLike.Basic
 
+#align_import data.fun_like.embedding from "leanprover-community/mathlib"@"c4658a649d216f57e99621708b09dcb3dcccbd23"
+
 /-!
 # Typeclass for a type `F` with an injective map to `A ↪ B`

c4658a64

chore: formatting issues (#4947)

Co-authored-by: Scott Morrison <scott.morrison@anu.edu.au> Co-authored-by: Parcly Taxel <reddeloostw@gmail.com>

5068808d

Diff

@@ -20,9 +20,9 @@ This typeclass is primarily for use by embeddings such as `RelEmbedding`.
 A typical type of embeddings should be declared as:
 ```
 structure MyEmbedding (A B : Type _) [MyClass A] [MyClass B] :=
-(toFun : A → B)
-(injective' : Function.Injective toFun)
-(map_op' : ∀ {x y : A}, toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
+  (toFun : A → B)
+  (injective' : Function.Injective toFun)
+  (map_op' : ∀ {x y : A}, toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
 
 namespace MyEmbedding
 
@@ -30,9 +30,9 @@ variables (A B : Type _) [MyClass A] [MyClass B]
 
 -- This instance is optional if you follow the "Embedding class" design below:
 instance : EmbeddingLike (MyEmbedding A B) A B :=
-{ coe := MyEmbedding.toFun,
-  coe_injective' := λ f g h, by cases f; cases g; congr',
-  injective' := MyEmbedding.injective' }
+  { coe := MyEmbedding.toFun,
+    coe_injective' := λ f g h, by cases f; cases g; congr',
+    injective' := MyEmbedding.injective' }
 
 /-- Helper instance for when there's too many metavariables to `EmbeddingLike.coe` directly. -/
 instance : CoeFun (MyEmbedding A B) (λ _, A → B) := ⟨MyEmbedding.toFun⟩
@@ -42,9 +42,9 @@ instance : CoeFun (MyEmbedding A B) (λ _, A → B) := ⟨MyEmbedding.toFun⟩
 /-- Copy of a `MyEmbedding` with a new `toFun` equal to the old one. Useful to fix definitional
 equalities. -/
 protected def copy (f : MyEmbedding A B) (f' : A → B) (h : f' = ⇑f) : MyEmbedding A B :=
-{ toFun := f',
-  injective' := h.symm ▸ f.injective',
-  map_op' := h.symm ▸ f.map_op' }
+  { toFun := f',
+    injective' := h.symm ▸ f.injective',
+    map_op' := h.symm ▸ f.map_op' }
 
 end MyEmbedding
 ```
@@ -76,10 +76,10 @@ MyEmbeddingClass.map_op
 
 -- You can replace `MyEmbedding.EmbeddingLike` with the below instance:
 instance : MyEmbeddingClass (MyEmbedding A B) A B :=
-{ coe := MyEmbedding.toFun,
-  coe_injective' := λ f g h, by cases f; cases g; congr',
-  injective' := MyEmbedding.injective',
-  map_op := MyEmbedding.map_op' }
+  { coe := MyEmbedding.toFun,
+    coe_injective' := λ f g h, by cases f; cases g; congr',
+    injective' := MyEmbedding.injective',
+    map_op := MyEmbedding.map_op' }
 
 -- [Insert `CoeFun`, `ext` and `copy` here]
 ```
@@ -108,11 +108,11 @@ MyEmbeddingClass.map_op
 
 -- You can also replace `MyEmbedding.EmbeddingLike` with the below instance:
 instance : CoolerEmbeddingClass (CoolerEmbedding A B) A B :=
-{ coe := CoolerEmbedding.toFun,
-  coe_injective' := λ f g h, by cases f; cases g; congr',
-  injective' := MyEmbedding.injective',
-  map_op := CoolerEmbedding.map_op',
-  map_cool := CoolerEmbedding.map_cool' }
+  { coe := CoolerEmbedding.toFun,
+    coe_injective' := λ f g h, by cases f; cases g; congr',
+    injective' := MyEmbedding.injective',
+    map_op := CoolerEmbedding.map_op',
+    map_cool := CoolerEmbedding.map_cool' }
 
 -- [Insert `CoeFun`, `ext` and `copy` here]
 ```

c4658a64

chore: add missing #align statements (#1902)

This PR is the result of a slight variant on the following "algorithm"

take all mathlib 3 names, remove _ and make all uppercase letters into lowercase
take all mathlib 4 names, remove _ and make all uppercase letters into lowercase
look for matches, and create pairs (original_lean3_name, OriginalLean4Name)
for pairs that do not have an align statement:
- use Lean 4 to lookup the file + position of the Lean 4 name
- add an #align statement just before the next empty line
manually fix some tiny mistakes (e.g., empty lines in proofs might cause the #align statement to have been inserted too early)

b72bb858

Diff

@@ -137,6 +137,7 @@ injective coercion to injective functions `α ↪ β`.
 class EmbeddingLike (F : Sort _) (α β : outParam (Sort _)) extends FunLike F α fun _ ↦ β where
   /-- The coercion to functions must produce injective functions. -/
   injective' : ∀ f : F, @Function.Injective α β (coe f)
+#align embedding_like EmbeddingLike
 
 namespace EmbeddingLike
 
@@ -144,14 +145,17 @@ variable {F α β γ : Sort _} [i : EmbeddingLike F α β]
 
 protected theorem injective (f : F) : Function.Injective f :=
   injective' f
+#align embedding_like.injective EmbeddingLike.injective
 
 @[simp]
 theorem apply_eq_iff_eq (f : F) {x y : α} : f x = f y ↔ x = y :=
   (EmbeddingLike.injective f).eq_iff
+#align embedding_like.apply_eq_iff_eq EmbeddingLike.apply_eq_iff_eq
 
 @[simp]
 theorem comp_injective {F : Sort _} [EmbeddingLike F β γ] (f : α → β) (e : F) :
     Function.Injective (e ∘ f) ↔ Function.Injective f :=
   (EmbeddingLike.injective e).of_comp_iff f
+#align embedding_like.comp_injective EmbeddingLike.comp_injective
 
 end EmbeddingLike

c4658a64

chore: Rename Type* to Type _ (#1866)

A bunch of docstrings were still mentioning Type*. This changes them to Type _.

50036b41

Diff

@@ -19,14 +19,14 @@ This typeclass is primarily for use by embeddings such as `RelEmbedding`.
 
 A typical type of embeddings should be declared as:
 ```
-structure MyEmbedding (A B : Type*) [MyClass A] [MyClass B] :=
+structure MyEmbedding (A B : Type _) [MyClass A] [MyClass B] :=
 (toFun : A → B)
 (injective' : Function.Injective toFun)
 (map_op' : ∀ {x y : A}, toFun (MyClass.op x y) = MyClass.op (toFun x) (toFun y))
 
 namespace MyEmbedding
 
-variables (A B : Type*) [MyClass A] [MyClass B]
+variables (A B : Type _) [MyClass A] [MyClass B]
 
 -- This instance is optional if you follow the "Embedding class" design below:
 instance : EmbeddingLike (MyEmbedding A B) A B :=
@@ -64,13 +64,13 @@ section
 
 /-- `MyEmbeddingClass F A B` states that `F` is a type of `MyClass.op`-preserving embeddings.
 You should extend this class when you extend `MyEmbedding`. -/
-class MyEmbeddingClass (F : Type*) (A B : outParam <| Type*) [MyClass A] [MyClass B]
+class MyEmbeddingClass (F : Type _) (A B : outParam <| Type _) [MyClass A] [MyClass B]
   extends EmbeddingLike F A B :=
 (map_op : ∀ (f : F) (x y : A), f (MyClass.op x y) = MyClass.op (f x) (f y))
 
 end
 
-@[simp] lemma map_op {F A B : Type*} [MyClass A] [MyClass B] [MyEmbeddingClass F A B]
+@[simp] lemma map_op {F A B : Type _} [MyClass A] [MyClass B] [MyEmbeddingClass F A B]
   (f : F) (x y : A) : f (MyClass.op x y) = MyClass.op (f x) (f y) :=
 MyEmbeddingClass.map_op
 
@@ -89,20 +89,20 @@ The second step is to add instances of your new `MyEmbeddingClass` for all types
 Typically, you can just declare a new class analogous to `MyEmbeddingClass`:
 
 ```
-structure CoolerEmbedding (A B : Type*) [CoolClass A] [CoolClass B]
+structure CoolerEmbedding (A B : Type _) [CoolClass A] [CoolClass B]
   extends MyEmbedding A B :=
 (map_cool' : toFun CoolClass.cool = CoolClass.cool)
 
 section
 set_option old_structure_cmd true
 
-class CoolerEmbeddingClass (F : Type*) (A B : outParam <| Type*) [CoolClass A] [CoolClass B]
+class CoolerEmbeddingClass (F : Type _) (A B : outParam <| Type _) [CoolClass A] [CoolClass B]
   extends MyEmbeddingClass F A B :=
 (map_cool : ∀ (f : F), f CoolClass.cool = CoolClass.cool)
 
 end
 
-@[simp] lemma map_cool {F A B : Type*} [CoolClass A] [CoolClass B] [CoolerEmbeddingClass F A B]
+@[simp] lemma map_cool {F A B : Type _} [CoolClass A] [CoolClass B] [CoolerEmbeddingClass F A B]
   (f : F) : f CoolClass.cool = CoolClass.cool :=
 MyEmbeddingClass.map_op
 
@@ -121,7 +121,7 @@ Then any declaration taking a specific type of morphisms as parameter can instea
 class you just defined:
 ```
 -- Compare with: lemma do_something (f : MyEmbedding A B) : sorry := sorry
-lemma do_something {F : Type*} [MyEmbeddingClass F A B] (f : F) : sorry := sorry
+lemma do_something {F : Type _} [MyEmbeddingClass F A B] (f : F) : sorry := sorry
 ```
 
 This means anything set up for `MyEmbedding`s will automatically work for `CoolerEmbeddingClass`es,

c4658a64

chore: fix more casing errors per naming scheme (#1232)

I've avoided anything under Tactic or test.

In correcting the names, I found Option.isNone_iff_eq_none duplicated between Std and Mathlib, so the Mathlib one has been removed.

Co-authored-by: Reid Barton <rwbarton@gmail.com>

31a56f75

Diff

@@ -37,7 +37,7 @@ instance : EmbeddingLike (MyEmbedding A B) A B :=
 /-- Helper instance for when there's too many metavariables to `EmbeddingLike.coe` directly. -/
 instance : CoeFun (MyEmbedding A B) (λ _, A → B) := ⟨MyEmbedding.toFun⟩
 
-@[ext] theorem ext {f g : MyEmbedding A B} (h : ∀ x, f x = g x) : f = g := fun_like.ext f g h
+@[ext] theorem ext {f g : MyEmbedding A B} (h : ∀ x, f x = g x) : f = g := FunLike.ext f g h
 
 /-- Copy of a `MyEmbedding` with a new `toFun` equal to the old one. Useful to fix definitional
 equalities. -/

c4658a64

chore: add source headers to ported theory files (#1094)

The script used to do this is included. The yaml file was obtained from https://raw.githubusercontent.com/wiki/leanprover-community/mathlib/mathlib4-port-status.md

f168625e

Diff

@@ -2,6 +2,11 @@
 Copyright (c) 2021 Anne Baanen. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Anne Baanen
+
+! This file was ported from Lean 3 source module data.fun_like.embedding
+! leanprover-community/mathlib commit c4658a649d216f57e99621708b09dcb3dcccbd23
+! Please do not edit these lines, except to modify the commit id
+! if you have ported upstream changes.
 -/
 import Mathlib.Data.FunLike.Basic

`data.fun_like.embedding` ⟷ `Mathlib.Data.FunLike.Embedding`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Important changes

Remaining issues

Slower (failing) search

`simp` not firing sometimes

Missing instances due to unification failing

Workaround for issues

Dependencies 5

data.fun_like.embedding ⟷ Mathlib.Data.FunLike.Embedding

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Important changes

Remaining issues

Slower (failing) search

simp not firing sometimes

Missing instances due to unification failing

Workaround for issues

Dependencies 5

`data.fun_like.embedding` ⟷ `Mathlib.Data.FunLike.Embedding`

`simp` not firing sometimes