data.rat.init | 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

f340f229

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

448144f7

bump to nightly-2024-02-27-08

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

cca8d078

Diff

@@ -77,10 +77,8 @@ instance : ToString ℚ :=
 unsafe instance : has_to_format ℚ :=
   ⟨coe ∘ Rat.repr⟩
 
-#print Rat.ext_iff /-
 theorem ext_iff {p q : ℚ} : p = q ↔ p.num = q.num ∧ p.den = q.den := by cases p; cases q; simp
 #align rat.ext_iff Rat.ext_iff
--/
 
 #print Rat.ext /-
 @[ext]

448144f7

bump to nightly-2023-09-24-06

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

5655435f

Diff

@@ -3,8 +3,8 @@ Copyright (c) 2019 Johannes Hölzl. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johannes Hölzl, Mario Carneiro
 -/
-import Mathbin.Tactic.Ext
-import Mathbin.Logic.Basic
+import Tactic.Ext
+import Logic.Basic
 
 #align_import data.rat.init from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"

448144f7

bump to nightly-2023-09-20-06

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

e28e6964

Diff

@@ -54,7 +54,7 @@ structure Rat where mk' ::
   num : ℤ
   den : ℕ
   Pos : 0 < denom
-  cop : Num.natAbs.coprime denom
+  cop : Num.natAbs.Coprime denom
 #align rat Rat
 -/

448144f7

bump to nightly-2023-07-20-09

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

9c56d0dd

Diff

@@ -2,15 +2,12 @@
 Copyright (c) 2019 Johannes Hölzl. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johannes Hölzl, Mario Carneiro
-
-! This file was ported from Lean 3 source module data.rat.init
-! 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.Tactic.Ext
 import Mathbin.Logic.Basic
 
+#align_import data.rat.init from "leanprover-community/mathlib"@"448144f7ae193a8990cb7473c9e9a01990f64ac7"
+
 /-!
 # The definition of the Rational Numbers

448144f7

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -61,7 +61,6 @@ structure Rat where mk' ::
 #align rat Rat
 -/
 
--- mathport name: exprℚ
 notation "ℚ" => Rat
 
 namespace Rat

448144f7

bump to nightly-2023-05-28-04

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

6797a637

Diff

@@ -82,11 +82,7 @@ unsafe instance : has_to_format ℚ :=
   ⟨coe ∘ Rat.repr⟩
 
 #print Rat.ext_iff /-
-theorem ext_iff {p q : ℚ} : p = q ↔ p.num = q.num ∧ p.den = q.den :=
-  by
-  cases p
-  cases q
-  simp
+theorem ext_iff {p q : ℚ} : p = q ↔ p.num = q.num ∧ p.den = q.den := by cases p; cases q; simp
 #align rat.ext_iff Rat.ext_iff
 -/

448144f7

bump to nightly-2023-02-21-16

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

1107b979

Changes in mathlib4

mathlib3

mathlib4

f340f229

feat: NNRat.cast (#11203)

Define the canonical coercion from the nonnegative rationals to any division semiring.

From LeanAPAP

1a5d1288

Diff

@@ -30,12 +30,44 @@ def NNRat := {q : ℚ // 0 ≤ q}
 
 @[inherit_doc] notation "ℚ≥0" => NNRat
 
+/-!
+### Cast from `NNRat`
+
+This section sets up the typeclasses necessary to declare the canonical embedding `ℚ≥0` to any
+semifield.
+-/
+
+/-- Typeclass for the canonical homomorphism `ℚ≥0 → K`.
+
+This should be considered as a notation typeclass. The sole purpose of this typeclass is to be
+extended by `DivisionSemiring`. -/
+class NNRatCast (K : Type*) where
+  /-- The canonical homomorphism `ℚ≥0 → K`.
+
+  Do not use directly. Use the coercion instead. -/
+  protected nnratCast : ℚ≥0 → K
+
+instance NNRat.instNNRatCast : NNRatCast ℚ≥0 where nnratCast q := q
+
+variable {K : Type*} [NNRatCast K]
+
+/-- Canonical homomorphism from `ℚ≥0` to a division semiring `K`.
+
+This is just the bare function in order to aid in creating instances of `DivisionSemiring`. -/
+@[coe, reducible, match_pattern] protected def NNRat.cast : ℚ≥0 → K := NNRatCast.nnratCast
+
+-- See note [coercion into rings]
+instance NNRatCast.toCoeTail [NNRatCast K] : CoeTail ℚ≥0 K where coe := NNRat.cast
+
+-- See note [coercion into rings]
+instance NNRatCast.toCoeHTCT [NNRatCast K] : CoeHTCT ℚ≥0 K where coe := NNRat.cast
+
+instance Rat.instNNRatCast : NNRatCast ℚ := ⟨Subtype.val⟩
+
 /-! ### Numerator and denominator of a nonnegative rational -/
 
 namespace NNRat
 
-instance instCoe : Coe ℚ≥0 ℚ := ⟨Subtype.val⟩
-
 /-- The numerator of a nonnegative rational. -/
 @[pp_dot] def num (q : ℚ≥0) : ℕ := (q : ℚ).num.natAbs
 #align nnrat.num NNRat.num
@@ -47,6 +79,9 @@ instance instCoe : Coe ℚ≥0 ℚ := ⟨Subtype.val⟩
 @[simp] lemma num_mk (q : ℚ) (hq : 0 ≤ q) : num ⟨q, hq⟩ = q.num.natAbs := rfl
 @[simp] lemma den_mk (q : ℚ) (hq : 0 ≤ q) : den ⟨q, hq⟩ = q.den := rfl
 
+@[norm_cast] lemma cast_id (n : ℚ≥0) : NNRat.cast n = n := rfl
+@[simp] lemma cast_eq_id : NNRat.cast = id := rfl
+
 end NNRat
 
 namespace Rat

f340f229

refactor(Rat): Streamline basic theory (#11504)

Rat has a long history in (and before) mathlib and as such its development is full of cruft. Now that NNRat is a thing, there is a need for the theory of Rat to be mimickable to yield the theory of NNRat, which is not currently the case.

Broadly, this PR aims at mirroring the Rat and NNRat declarations. It achieves this by:

Relying more on Rat.num and Rat.den, and less on the structure representation of Rat
Abandoning the vestigial Rat.Nonneg (which was replaced in Std by a new development of the order on Rat)
Renaming many Rat lemmas with dubious names. This creates quite a lot of conflicts with Std lemmas, whose names are themselves dubious. I am priming the relevant new mathlib names and leaving TODOs to fix the Std names.
Handling most of the Rat porting notes

Reduce the diff of #11203

28bea03d

Diff

@@ -1,18 +1,59 @@
 /-
 Copyright (c) 2019 Johannes Hölzl. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
-Authors: Johannes Hölzl, Mario Carneiro
+Authors: Johannes Hölzl, Mario Carneiro, Yaël Dillies
 -/
+import Mathlib.Init.Data.Nat.Notation
 import Mathlib.Mathport.Rename
-import Std.Data.Rat.Basic
+import Mathlib.Tactic.Lemma
+import Mathlib.Tactic.ProjectionNotation
+import Mathlib.Tactic.TypeStar
+import Std.Classes.RatCast
 
 #align_import data.rat.init from "leanprover-community/mathlib"@"f340f229b1f461aa1c8ee11e0a172d0a3b301a4a"
 
 /-!
-# Notation for the rational numbers -/
+# Basic definitions around the rational numbers
 
-namespace Rat
+This file declares `ℚ` notation for the rationals and defines the nonnegative rationals `ℚ≥0`.
+
+This file is eligible to upstreaming to Std.
+-/
 
 @[inherit_doc] notation "ℚ" => Rat
 
 #align rat.denom Rat.den
+
+/-- Nonnegative rational numbers. -/
+def NNRat := {q : ℚ // 0 ≤ q}
+#align nnrat NNRat
+
+@[inherit_doc] notation "ℚ≥0" => NNRat
+
+/-! ### Numerator and denominator of a nonnegative rational -/
+
+namespace NNRat
+
+instance instCoe : Coe ℚ≥0 ℚ := ⟨Subtype.val⟩
+
+/-- The numerator of a nonnegative rational. -/
+@[pp_dot] def num (q : ℚ≥0) : ℕ := (q : ℚ).num.natAbs
+#align nnrat.num NNRat.num
+
+/-- The denominator of a nonnegative rational. -/
+@[pp_dot] def den (q : ℚ≥0) : ℕ := (q : ℚ).den
+#align nnrat.denom NNRat.den
+
+@[simp] lemma num_mk (q : ℚ) (hq : 0 ≤ q) : num ⟨q, hq⟩ = q.num.natAbs := rfl
+@[simp] lemma den_mk (q : ℚ) (hq : 0 ≤ q) : den ⟨q, hq⟩ = q.den := rfl
+
+end NNRat
+
+namespace Rat
+
+@[norm_cast] lemma cast_id (n : ℚ) : Rat.cast n = n := rfl
+@[simp] lemma cast_eq_id : Rat.cast = id := rfl
+#align rat.cast_id Rat.cast_id
+#align rat.cast_eq_id Rat.cast_eq_id
+
+end Rat

f340f229

chore: fix imports (#8538)

f659b7bb

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johannes Hölzl, Mario Carneiro
 -/
 import Mathlib.Mathport.Rename
-import Std.Data.Rat
+import Std.Data.Rat.Basic
 
 #align_import data.rat.init from "leanprover-community/mathlib"@"f340f229b1f461aa1c8ee11e0a172d0a3b301a4a"

f340f229

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) 2019 Johannes Hölzl. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johannes Hölzl, Mario Carneiro
-
-! This file was ported from Lean 3 source module data.rat.init
-! leanprover-community/mathlib commit f340f229b1f461aa1c8ee11e0a172d0a3b301a4a
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Mathport.Rename
 import Std.Data.Rat
 
+#align_import data.rat.init from "leanprover-community/mathlib"@"f340f229b1f461aa1c8ee11e0a172d0a3b301a4a"
+
 /-!
 # Notation for the rational numbers -/

f340f229

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) 2019 Johannes Hölzl. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Johannes Hölzl, Mario Carneiro
+
+! This file was ported from Lean 3 source module data.rat.init
+! leanprover-community/mathlib commit f340f229b1f461aa1c8ee11e0a172d0a3b301a4a
+! Please do not edit these lines, except to modify the commit id
+! if you have ported upstream changes.
 -/
 import Mathlib.Mathport.Rename
 import Std.Data.Rat

`data.rat.init` ⟷ `Mathlib.Data.Rat.Init`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies

data.rat.init ⟷ Mathlib.Data.Rat.Init

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies

`data.rat.init` ⟷ `Mathlib.Data.Rat.Init`