data.nat.factorial.double_factorial | 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

7daeaf30

(last sync)

Changes in mathlib3port

mathlib3

mathlib3port

33c67ae6

bump to nightly-2024-04-07-08

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

b03b8656

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
 -/
 import Data.Nat.Factorial.Basic
-import Algebra.BigOperators.Order
+import Algebra.Order.BigOperators.Group.Finset
 import Tactic.Ring
 
 #align_import data.nat.factorial.double_factorial from "leanprover-community/mathlib"@"33c67ae661dd8988516ff7f247b0be3018cdd952"

33c67ae6

bump to nightly-2024-04-06-08

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

e34029c9

Diff

@@ -66,7 +66,7 @@ theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
   | 0 => rfl
   | n + 1 =>
     by
-    rw [mul_add, mul_one, double_factorial_add_two, factorial, pow_succ, double_factorial_two_mul,
+    rw [mul_add, mul_one, double_factorial_add_two, factorial, pow_succ', double_factorial_two_mul,
       succ_eq_add_one]
     ring
 #align nat.double_factorial_two_mul Nat.doubleFactorial_two_mul

33c67ae6

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) 2023 Jake Levinson. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
 -/
-import Mathbin.Data.Nat.Factorial.Basic
-import Mathbin.Algebra.BigOperators.Order
-import Mathbin.Tactic.Ring
+import Data.Nat.Factorial.Basic
+import Algebra.BigOperators.Order
+import Tactic.Ring
 
 #align_import data.nat.factorial.double_factorial from "leanprover-community/mathlib"@"33c67ae661dd8988516ff7f247b0be3018cdd952"

33c67ae6

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) 2023 Jake Levinson. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
-
-! This file was ported from Lean 3 source module data.nat.factorial.double_factorial
-! leanprover-community/mathlib commit 33c67ae661dd8988516ff7f247b0be3018cdd952
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Data.Nat.Factorial.Basic
 import Mathbin.Algebra.BigOperators.Order
 import Mathbin.Tactic.Ring
 
+#align_import data.nat.factorial.double_factorial from "leanprover-community/mathlib"@"33c67ae661dd8988516ff7f247b0be3018cdd952"
+
 /-!
 # Double factorials

33c67ae6

bump to nightly-2023-06-13-21

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

829520ac

Diff

@@ -41,7 +41,6 @@ def doubleFactorial : ℕ → ℕ
 #align nat.double_factorial Nat.doubleFactorial
 -/
 
--- mathport name: nat.double_factorial
 -- This notation is `\!!` not two !'s
 scoped notation:10000 n "‼" => Nat.doubleFactorial n

33c67ae6

bump to nightly-2023-06-10-07

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

3fdc57bc

Diff

@@ -90,7 +90,8 @@ theorem doubleFactorial_eq_prod_even : ∀ n : ℕ, (2 * n)‼ = ∏ i in Finset
 -/
 
 #print Nat.doubleFactorial_eq_prod_odd /-
-theorem doubleFactorial_eq_prod_odd : ∀ n : ℕ, (2 * n + 1)‼ = ∏ i in Finset.range n, 2 * (i + 1) + 1
+theorem doubleFactorial_eq_prod_odd :
+    ∀ n : ℕ, (2 * n + 1)‼ = ∏ i in Finset.range n, (2 * (i + 1) + 1)
   | 0 => rfl
   | n + 1 =>
     by

33c67ae6

bump to nightly-2023-05-28-18

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

8d353152

Diff

@@ -27,7 +27,7 @@ This file defines the double factorial,
 -/
 
 
-open Nat
+open scoped Nat
 
 namespace Nat
 
@@ -76,7 +76,7 @@ theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
 #align nat.double_factorial_two_mul Nat.doubleFactorial_two_mul
 -/
 
-open BigOperators
+open scoped BigOperators
 
 #print Nat.doubleFactorial_eq_prod_even /-
 theorem doubleFactorial_eq_prod_even : ∀ n : ℕ, (2 * n)‼ = ∏ i in Finset.range n, 2 * (i + 1)

33c67ae6

bump to nightly-2023-05-21-03

mathlib commit https://github.com/leanprover-community/mathlib/commit/33c67ae661dd8988516ff7f247b0be3018cdd952

7b1466d5

Diff

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
 
 ! This file was ported from Lean 3 source module data.nat.factorial.double_factorial
-! leanprover-community/mathlib commit 7daeaf3072304c498b653628add84a88d0e78767
+! leanprover-community/mathlib commit 33c67ae661dd8988516ff7f247b0be3018cdd952
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -15,6 +15,9 @@ import Mathbin.Tactic.Ring
 /-!
 # Double factorials
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 This file defines the double factorial,
   `n‼ := n * (n - 2) * (n - 4) * ...`.

7daeaf30

bump to nightly-2023-05-19-18

mathlib commit https://github.com/leanprover-community/mathlib/commit/95a87616d63b3cb49d3fe678d416fbe9c4217bf4

8fdc7bef

Diff

@@ -28,6 +28,7 @@ open Nat
 
 namespace Nat
 
+#print Nat.doubleFactorial /-
 /-- `nat.double_factorial n` is the double factorial of `n`. -/
 @[simp]
 def doubleFactorial : ℕ → ℕ
@@ -35,25 +36,33 @@ def doubleFactorial : ℕ → ℕ
   | 1 => 1
   | k + 2 => (k + 2) * double_factorial k
 #align nat.double_factorial Nat.doubleFactorial
+-/
 
 -- mathport name: nat.double_factorial
 -- This notation is `\!!` not two !'s
 scoped notation:10000 n "‼" => Nat.doubleFactorial n
 
+#print Nat.doubleFactorial_add_two /-
 theorem doubleFactorial_add_two (n : ℕ) : (n + 2)‼ = (n + 2) * n‼ :=
   rfl
 #align nat.double_factorial_add_two Nat.doubleFactorial_add_two
+-/
 
+#print Nat.doubleFactorial_add_one /-
 theorem doubleFactorial_add_one (n : ℕ) : (n + 1)‼ = (n + 1) * (n - 1)‼ := by cases n <;> rfl
 #align nat.double_factorial_add_one Nat.doubleFactorial_add_one
+-/
 
+#print Nat.factorial_eq_mul_doubleFactorial /-
 theorem factorial_eq_mul_doubleFactorial : ∀ n : ℕ, (n + 1)! = (n + 1)‼ * n‼
   | 0 => rfl
   | k + 1 => by
     rw [double_factorial_add_two, factorial, factorial_eq_mul_double_factorial, mul_comm _ k‼,
       mul_assoc]
 #align nat.factorial_eq_mul_double_factorial Nat.factorial_eq_mul_doubleFactorial
+-/
 
+#print Nat.doubleFactorial_two_mul /-
 theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
   | 0 => rfl
   | n + 1 =>
@@ -62,9 +71,11 @@ theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
       succ_eq_add_one]
     ring
 #align nat.double_factorial_two_mul Nat.doubleFactorial_two_mul
+-/
 
 open BigOperators
 
+#print Nat.doubleFactorial_eq_prod_even /-
 theorem doubleFactorial_eq_prod_even : ∀ n : ℕ, (2 * n)‼ = ∏ i in Finset.range n, 2 * (i + 1)
   | 0 => rfl
   | n + 1 =>
@@ -73,7 +84,9 @@ theorem doubleFactorial_eq_prod_even : ∀ n : ℕ, (2 * n)‼ = ∏ i in Finset
       (by ring : 2 * (n + 1) = 2 * n + 2)]
     rfl
 #align nat.double_factorial_eq_prod_even Nat.doubleFactorial_eq_prod_even
+-/
 
+#print Nat.doubleFactorial_eq_prod_odd /-
 theorem doubleFactorial_eq_prod_odd : ∀ n : ℕ, (2 * n + 1)‼ = ∏ i in Finset.range n, 2 * (i + 1) + 1
   | 0 => rfl
   | n + 1 =>
@@ -82,6 +95,7 @@ theorem doubleFactorial_eq_prod_odd : ∀ n : ℕ, (2 * n + 1)‼ = ∏ i in Fin
       (by ring : 2 * (n + 1) + 1 = 2 * n + 1 + 2)]
     rfl
 #align nat.double_factorial_eq_prod_odd Nat.doubleFactorial_eq_prod_odd
+-/
 
 end Nat

7daeaf30

bump to nightly-2023-05-19-03

mathlib commit https://github.com/leanprover-community/mathlib/commit/95a87616d63b3cb49d3fe678d416fbe9c4217bf4

9a2fedb8

Changes in mathlib4

mathlib3

mathlib4

7daeaf30

chore: cleanup TODOs around leanprover/lean4#3060 (#10198)

Mathlib is now using v4.6.0-rc1, which includes the fix in leanprover/lean4#3060

bbb28935

Diff

@@ -95,13 +95,11 @@ open Lean Meta Qq
 /-- Extension for `Nat.doubleFactorial`. -/
 @[positivity Nat.doubleFactorial _]
 def evalDoubleFactorial : PositivityExt where eval {u α} _ _ e := do
-  if let 0 := u then -- lean4#3060 means we can't combine this with the match below
-    match α, e with
-    | ~q(ℕ), ~q(Nat.doubleFactorial $n) =>
-      assumeInstancesCommute
-      return .positive q(Nat.doubleFactorial_pos $n)
-    | _, _ => throwError "not Nat.doubleFactorial"
-  else throwError "not Nat.doubleFactorial"
+  match u, α, e with
+  | 0, ~q(ℕ), ~q(Nat.doubleFactorial $n) =>
+    assumeInstancesCommute
+    return .positive q(Nat.doubleFactorial_pos $n)
+  | _, _ => throwError "not Nat.doubleFactorial"
 
 example (n : ℕ) : 0 < n‼ := by positivity

7daeaf30

doc: @[inherit_doc] on notations (#9942)

Make all the notations that unambiguously should inherit the docstring of their definition actually inherit it.

Also write a few docstrings by hand. I only wrote the ones I was competent to write and which I was sure of. Some docstrings come from mathlib3 as they were lost during the early port.

This PR is only intended as a first pass There are many more docstrings to add.

08f7e99d

Diff

@@ -35,7 +35,7 @@ def doubleFactorial : ℕ → ℕ
 #align nat.double_factorial Nat.doubleFactorial
 
 -- This notation is `\!!` not two !'s
-scoped notation:10000 n "‼" => Nat.doubleFactorial n
+@[inherit_doc] scoped notation:10000 n "‼" => Nat.doubleFactorial n
 
 lemma doubleFactorial_pos : ∀ n, 0 < n‼
   | 0 | 1 => zero_lt_one

7daeaf30

chore: reduce imports (#9830)

This uses the improved shake script from #9772 to reduce imports across mathlib. The corresponding noshake.json file has been added to #9772.

Co-authored-by: Mario Carneiro <di.gama@gmail.com>

f4c4ca61

Diff

@@ -4,8 +4,9 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
 -/
 import Mathlib.Data.Nat.Factorial.Basic
-import Mathlib.Algebra.BigOperators.Order
+import Mathlib.Algebra.BigOperators.Basic
 import Mathlib.Tactic.Ring
+import Mathlib.Tactic.Positivity.Core
 
 #align_import data.nat.factorial.double_factorial from "leanprover-community/mathlib"@"7daeaf3072304c498b653628add84a88d0e78767"

7daeaf30

fix: patch for std4#198 (more mul lemmas for Nat) (#6204)

Co-authored-by: Scott Morrison <scott.morrison@gmail.com>

2f63d25e

Diff

@@ -57,7 +57,7 @@ theorem factorial_eq_mul_doubleFactorial : ∀ n : ℕ, (n + 1)! = (n + 1)‼ *
 lemma doubleFactorial_le_factorial : ∀ n, n‼ ≤ n !
   | 0 => le_rfl
   | n + 1 => by
-    rw [factorial_eq_mul_doubleFactorial]; exact le_mul_of_pos_right n.doubleFactorial_pos
+    rw [factorial_eq_mul_doubleFactorial]; exact Nat.le_mul_of_pos_right _ n.doubleFactorial_pos
 
 theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
   | 0 => rfl

7daeaf30

feat: The double factorial is positive (#9102)

and other basic results. Also include a positivity extension to encode that new result.

From LeanAPAP

61efe6de

Diff

@@ -36,6 +36,10 @@ def doubleFactorial : ℕ → ℕ
 -- This notation is `\!!` not two !'s
 scoped notation:10000 n "‼" => Nat.doubleFactorial n
 
+lemma doubleFactorial_pos : ∀ n, 0 < n‼
+  | 0 | 1 => zero_lt_one
+  | _n + 2 => mul_pos (succ_pos _) (doubleFactorial_pos _)
+
 theorem doubleFactorial_add_two (n : ℕ) : (n + 2)‼ = (n + 2) * n‼ :=
   rfl
 #align nat.double_factorial_add_two Nat.doubleFactorial_add_two
@@ -50,6 +54,11 @@ theorem factorial_eq_mul_doubleFactorial : ∀ n : ℕ, (n + 1)! = (n + 1)‼ *
       mul_assoc]
 #align nat.factorial_eq_mul_double_factorial Nat.factorial_eq_mul_doubleFactorial
 
+lemma doubleFactorial_le_factorial : ∀ n, n‼ ≤ n !
+  | 0 => le_rfl
+  | n + 1 => by
+    rw [factorial_eq_mul_doubleFactorial]; exact le_mul_of_pos_right n.doubleFactorial_pos
+
 theorem doubleFactorial_two_mul : ∀ n : ℕ, (2 * n)‼ = 2 ^ n * n !
   | 0 => rfl
   | n + 1 => by
@@ -78,3 +87,21 @@ theorem doubleFactorial_eq_prod_odd :
 #align nat.double_factorial_eq_prod_odd Nat.doubleFactorial_eq_prod_odd
 
 end Nat
+
+namespace Mathlib.Meta.Positivity
+open Lean Meta Qq
+
+/-- Extension for `Nat.doubleFactorial`. -/
+@[positivity Nat.doubleFactorial _]
+def evalDoubleFactorial : PositivityExt where eval {u α} _ _ e := do
+  if let 0 := u then -- lean4#3060 means we can't combine this with the match below
+    match α, e with
+    | ~q(ℕ), ~q(Nat.doubleFactorial $n) =>
+      assumeInstancesCommute
+      return .positive q(Nat.doubleFactorial_pos $n)
+    | _, _ => throwError "not Nat.doubleFactorial"
+  else throwError "not Nat.doubleFactorial"
+
+example (n : ℕ) : 0 < n‼ := by positivity
+
+end Mathlib.Meta.Positivity

7daeaf30

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

@@ -2,16 +2,13 @@
 Copyright (c) 2023 Jake Levinson. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Jake Levinson
-
-! This file was ported from Lean 3 source module data.nat.factorial.double_factorial
-! leanprover-community/mathlib commit 7daeaf3072304c498b653628add84a88d0e78767
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Data.Nat.Factorial.Basic
 import Mathlib.Algebra.BigOperators.Order
 import Mathlib.Tactic.Ring
 
+#align_import data.nat.factorial.double_factorial from "leanprover-community/mathlib"@"7daeaf3072304c498b653628add84a88d0e78767"
+
 /-!
 # Double factorials

7daeaf30

feat: port Data.Nat.Factorial.DoubleFactorial (#4117)

8c878fe1

`data.nat.factorial.double_factorial` ⟷ `Mathlib.Data.Nat.Factorial.DoubleFactorial`

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 3 + 206

data.nat.factorial.double_factorial ⟷ Mathlib.Data.Nat.Factorial.DoubleFactorial

Changes since the initial port

Changes in mathlib3

Changes in mathlib3port

Changes in mathlib4

Dependencies 3 + 206

`data.nat.factorial.double_factorial` ⟷ `Mathlib.Data.Nat.Factorial.DoubleFactorial`