testing.slim_check.gen ⟷ Mathlib.Testing.SlimCheck.Gen

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

@@ -4,8 +4,8 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Simon Hudon
 -/
 import Control.Random
-import Control.Uliftable
-import Data.List.BigOperators.Lemmas
+import Control.ULiftable
+import Algebra.BigOperators.List.Lemmas
 import Data.List.Perm
 
 #align_import testing.slim_check.gen from "leanprover-community/mathlib"@"9240e8be927a0955b9a82c6c85ef499ee3a626b8"

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

@@ -195,7 +195,7 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
         List.length_le_sum_of_one_le _ fun i => by simp; intros; assumption
   have : 0 ≤ s - 1 := le_tsub_of_add_le_right ha
   ULiftable.adaptUp Gen.{0} Gen.{u} (chooseNat 0 (s - 1) this) fun i =>
-    freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁  <;> exact ha)
+    freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁ <;> exact ha)
 #align slim_check.gen.freq SlimCheck.Gen.freq
 
 /- ./././Mathport/Syntax/Translate/Expr.lean:177:8: unsupported: ambiguous notation -/

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

@@ -3,10 +3,10 @@ Copyright (c) 2020 Simon Hudon. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Simon Hudon
 -/
-import Mathbin.Control.Random
-import Mathbin.Control.Uliftable
-import Mathbin.Data.List.BigOperators.Lemmas
-import Mathbin.Data.List.Perm
+import Control.Random
+import Control.Uliftable
+import Data.List.BigOperators.Lemmas
+import Data.List.Perm
 
 #align_import testing.slim_check.gen from "leanprover-community/mathlib"@"9240e8be927a0955b9a82c6c85ef499ee3a626b8"
 

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

@@ -2,17 +2,14 @@
 Copyright (c) 2020 Simon Hudon. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Simon Hudon
-
-! This file was ported from Lean 3 source module testing.slim_check.gen
-! leanprover-community/mathlib commit 9240e8be927a0955b9a82c6c85ef499ee3a626b8
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Control.Random
 import Mathbin.Control.Uliftable
 import Mathbin.Data.List.BigOperators.Lemmas
 import Mathbin.Data.List.Perm
 
+#align_import testing.slim_check.gen from "leanprover-community/mathlib"@"9240e8be927a0955b9a82c6c85ef499ee3a626b8"
+
 /-!
 # `gen` Monad
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/9240e8be927a0955b9a82c6c85ef499ee3a626b8

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Simon Hudon
 
 ! This file was ported from Lean 3 source module testing.slim_check.gen
-! leanprover-community/mathlib commit 23f67f2fd1b092739d7fbfcdfaab65ea2783a39d
+! leanprover-community/mathlib commit 9240e8be927a0955b9a82c6c85ef499ee3a626b8
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.
 -/
@@ -16,6 +16,9 @@ import Mathbin.Data.List.Perm
 /-!
 # `gen` Monad
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 This monad is used to formulate randomized computations with a parameter
 to specify the desired size of the result.
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/f2ad3645af9effcdb587637dc28a6074edc813f9

@@ -103,12 +103,12 @@ def chooseNat' (x y : ℕ) (p : x < y) : Gen (Set.Ico x y) :=
 
 open Nat
 
-instance : Uliftable Gen.{u} Gen.{v} :=
+instance : ULiftable Gen.{u} Gen.{v} :=
   ReaderT.uliftable' (Equiv.ulift.trans Equiv.ulift.symm)
 
 instance : HasOrelse Gen.{u} :=
   ⟨fun α x y => do
-    let b ← Uliftable.up <| chooseAny Bool
+    let b ← ULiftable.up <| chooseAny Bool
     if b then x else y⟩
 
 variable {α}
@@ -139,7 +139,7 @@ by the size parameter of `gen`. -/
 def listOf (cmd : Gen α) : Gen (List α) :=
   sized fun sz => do
     do
-      let ⟨n⟩ ← Uliftable.up <| choose_nat 0 (sz + 1) (by decide)
+      let ⟨n⟩ ← ULiftable.up <| choose_nat 0 (sz + 1) (by decide)
       let v ← vector_of n cmd
       return v
 #align slim_check.gen.list_of SlimCheck.Gen.listOf
@@ -150,7 +150,7 @@ open ULift
 #print SlimCheck.Gen.oneOf /-
 /-- Given a list of example generators, choose one to create an example. -/
 def oneOf (xs : List (Gen α)) (pos : 0 < xs.length) : Gen α := do
-  let ⟨⟨n, h, h'⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
+  let ⟨⟨n, h, h'⟩⟩ ← ULiftable.up <| chooseNat' 0 xs.length Pos
   List.nthLe xs n h'
 #align slim_check.gen.one_of SlimCheck.Gen.oneOf
 -/
@@ -158,7 +158,7 @@ def oneOf (xs : List (Gen α)) (pos : 0 < xs.length) : Gen α := do
 #print SlimCheck.Gen.elements /-
 /-- Given a list of example generators, choose one to create an example. -/
 def elements (xs : List α) (pos : 0 < xs.length) : Gen α := do
-  let ⟨⟨n, h₀, h₁⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
+  let ⟨⟨n, h₀, h₁⟩⟩ ← ULiftable.up <| chooseNat' 0 xs.length Pos
   pure <| List.nthLe xs n h₁
 #align slim_check.gen.elements SlimCheck.Gen.elements
 -/
@@ -194,7 +194,7 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
       List.length_map (Subtype.val ∘ Prod.fst) xs ▸
         List.length_le_sum_of_one_le _ fun i => by simp; intros; assumption
   have : 0 ≤ s - 1 := le_tsub_of_add_le_right ha
-  Uliftable.adaptUp Gen.{0} Gen.{u} (chooseNat 0 (s - 1) this) fun i =>
+  ULiftable.adaptUp Gen.{0} Gen.{u} (chooseNat 0 (s - 1) this) fun i =>
     freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁  <;> exact ha)
 #align slim_check.gen.freq SlimCheck.Gen.freq
 
@@ -205,7 +205,7 @@ def permutationOf {α : Type u} : ∀ xs : List α, Gen (Subtype <| List.Perm xs
   | [] => pure ⟨[], List.Perm.nil⟩
   | x::xs => do
     let ⟨xs', h⟩ ← permutation_of xs
-    let ⟨⟨n, _, h'⟩⟩ ← Uliftable.up <| chooseNat 0 xs'.length (by decide)
+    let ⟨⟨n, _, h'⟩⟩ ← ULiftable.up <| chooseNat 0 xs'.length (by decide)
     pure
         ⟨List.insertNth n x xs',
           List.Perm.trans (List.Perm.cons _ h) (List.perm_insertNth _ _ h').symm⟩

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

@@ -56,7 +56,6 @@ deriving Monad, LawfulMonad
 
 variable (α : Type u)
 
--- mathport name: «expr .. »
 local infixl:41 " .. " => Set.Icc
 
 /-- Execute a `gen` inside the `io` monad using `i` as the example
@@ -134,6 +133,7 @@ def vectorOf : ∀ (n : ℕ) (cmd : Gen α), Gen (Vector α n)
   | succ n, cmd => Vector.cons <$> cmd <*> vector_of n cmd
 #align slim_check.gen.vector_of SlimCheck.Gen.vectorOf
 
+#print SlimCheck.Gen.listOf /-
 /-- Create a list of examples using `cmd`. The size is controlled
 by the size parameter of `gen`. -/
 def listOf (cmd : Gen α) : Gen (List α) :=
@@ -143,20 +143,25 @@ def listOf (cmd : Gen α) : Gen (List α) :=
       let v ← vector_of n cmd
       return v
 #align slim_check.gen.list_of SlimCheck.Gen.listOf
+-/
 
 open ULift
 
+#print SlimCheck.Gen.oneOf /-
 /-- Given a list of example generators, choose one to create an example. -/
 def oneOf (xs : List (Gen α)) (pos : 0 < xs.length) : Gen α := do
   let ⟨⟨n, h, h'⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
   List.nthLe xs n h'
 #align slim_check.gen.one_of SlimCheck.Gen.oneOf
+-/
 
+#print SlimCheck.Gen.elements /-
 /-- Given a list of example generators, choose one to create an example. -/
 def elements (xs : List α) (pos : 0 < xs.length) : Gen α := do
   let ⟨⟨n, h₀, h₁⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
   pure <| List.nthLe xs n h₁
 #align slim_check.gen.elements SlimCheck.Gen.elements
+-/
 
 /- ./././Mathport/Syntax/Translate/Expr.lean:177:8: unsupported: ambiguous notation -/
 /-- `freq_aux xs i _` takes a weighted list of generator and a number meant to select one of the
@@ -194,6 +199,7 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
 #align slim_check.gen.freq SlimCheck.Gen.freq
 
 /- ./././Mathport/Syntax/Translate/Expr.lean:177:8: unsupported: ambiguous notation -/
+#print SlimCheck.Gen.permutationOf /-
 /-- Generate a random permutation of a given list. -/
 def permutationOf {α : Type u} : ∀ xs : List α, Gen (Subtype <| List.Perm xs)
   | [] => pure ⟨[], List.Perm.nil⟩
@@ -204,6 +210,7 @@ def permutationOf {α : Type u} : ∀ xs : List α, Gen (Subtype <| List.Perm xs
         ⟨List.insertNth n x xs',
           List.Perm.trans (List.Perm.cons _ h) (List.perm_insertNth _ _ h').symm⟩
 #align slim_check.gen.permutation_of SlimCheck.Gen.permutationOf
+-/
 
 end Gen
 

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

@@ -49,7 +49,8 @@ It has a `nat` parameter so that the caller can decide on the
 size of the examples. -/
 @[reducible]
 def Gen (α : Type u) :=
-  ReaderT (ULift ℕ) Rand α deriving Monad, LawfulMonad
+  ReaderT (ULift ℕ) Rand α
+deriving Monad, LawfulMonad
 #align slim_check.gen SlimCheck.Gen
 -/
 
@@ -186,10 +187,10 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
   have ha : 1 ≤ s :=
     le_trans Pos <|
       List.length_map (Subtype.val ∘ Prod.fst) xs ▸
-        List.length_le_sum_of_one_le _ fun i => by simp; intros ; assumption
+        List.length_le_sum_of_one_le _ fun i => by simp; intros; assumption
   have : 0 ≤ s - 1 := le_tsub_of_add_le_right ha
   Uliftable.adaptUp Gen.{0} Gen.{u} (chooseNat 0 (s - 1) this) fun i =>
-    freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁ <;> exact ha)
+    freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁  <;> exact ha)
 #align slim_check.gen.freq SlimCheck.Gen.freq
 
 /- ./././Mathport/Syntax/Translate/Expr.lean:177:8: unsupported: ambiguous notation -/

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

@@ -77,10 +77,12 @@ def chooseAny [Random α] : Gen α :=
 
 variable {α} [Preorder α]
 
+#print SlimCheck.Gen.choose /-
 /-- Lift `random.random_r` to the `gen` monad. -/
 def choose [BoundedRandom α] (x y : α) (p : x ≤ y) : Gen (x .. y) :=
   ⟨fun _ => Rand.randomR x y p⟩
 #align slim_check.gen.choose SlimCheck.Gen.choose
+-/
 
 end Rand
 

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

@@ -77,12 +77,6 @@ def chooseAny [Random α] : Gen α :=
 
 variable {α} [Preorder α]
 
-/- warning: slim_check.gen.choose -> SlimCheck.Gen.choose is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u1}} [_inst_1 : Preorder.{u1} α] [_inst_2 : BoundedRandom.{u1} α _inst_1] (x : α) (y : α), (LE.le.{u1} α (Preorder.toHasLe.{u1} α _inst_1) x y) -> (SlimCheck.Gen.{u1} (coeSort.{succ u1, succ (succ u1)} (Set.{u1} α) Type.{u1} (Set.hasCoeToSort.{u1} α) (Set.Icc.{u1} α _inst_1 x y)))
-but is expected to have type
-  forall (α : Type.{u1}) [_inst_1 : Preorder.{u1} α] [_inst_2 : BoundedRandom.{u1} α _inst_1] (x : α) (y : α), (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) x y) -> (SlimCheck.Gen.{u1} (Subtype.{succ u1} α (fun (a : α) => And (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) x a) (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) a y))))
-Case conversion may be inaccurate. Consider using '#align slim_check.gen.choose SlimCheck.Gen.chooseₓ'. -/
 /-- Lift `random.random_r` to the `gen` monad. -/
 def choose [BoundedRandom α] (x y : α) (p : x ≤ y) : Gen (x .. y) :=
   ⟨fun _ => Rand.randomR x y p⟩
@@ -137,12 +131,6 @@ def vectorOf : ∀ (n : ℕ) (cmd : Gen α), Gen (Vector α n)
   | succ n, cmd => Vector.cons <$> cmd <*> vector_of n cmd
 #align slim_check.gen.vector_of SlimCheck.Gen.vectorOf
 
-/- warning: slim_check.gen.list_of -> SlimCheck.Gen.listOf is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u}}, (SlimCheck.Gen.{u} α) -> (SlimCheck.Gen.{u} (List.{u} α))
-but is expected to have type
-  forall {α : Type}, (SlimCheck.Gen.{0} α) -> (SlimCheck.Gen.{0} (List.{0} α))
-Case conversion may be inaccurate. Consider using '#align slim_check.gen.list_of SlimCheck.Gen.listOfₓ'. -/
 /-- Create a list of examples using `cmd`. The size is controlled
 by the size parameter of `gen`. -/
 def listOf (cmd : Gen α) : Gen (List α) :=
@@ -155,24 +143,12 @@ def listOf (cmd : Gen α) : Gen (List α) :=
 
 open ULift
 
-/- warning: slim_check.gen.one_of -> SlimCheck.Gen.oneOf is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u}} (xs : List.{u} (SlimCheck.Gen.{u} α)), (LT.lt.{0} Nat Nat.hasLt (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) (List.length.{u} (SlimCheck.Gen.{u} α) xs)) -> (SlimCheck.Gen.{u} α)
-but is expected to have type
-  forall {α : Type} (xs : Array.{0} (SlimCheck.Gen.{0} α)), (autoParam.{0} (LT.lt.{0} Nat instLTNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) (Array.size.{0} (SlimCheck.Gen.{0} α) xs)) _auto._@.Mathlib.Testing.SlimCheck.Gen._hyg.572) -> (SlimCheck.Gen.{0} α)
-Case conversion may be inaccurate. Consider using '#align slim_check.gen.one_of SlimCheck.Gen.oneOfₓ'. -/
 /-- Given a list of example generators, choose one to create an example. -/
 def oneOf (xs : List (Gen α)) (pos : 0 < xs.length) : Gen α := do
   let ⟨⟨n, h, h'⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
   List.nthLe xs n h'
 #align slim_check.gen.one_of SlimCheck.Gen.oneOf
 
-/- warning: slim_check.gen.elements -> SlimCheck.Gen.elements is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u}} (xs : List.{u} α), (LT.lt.{0} Nat Nat.hasLt (OfNat.ofNat.{0} Nat 0 (OfNat.mk.{0} Nat 0 (Zero.zero.{0} Nat Nat.hasZero))) (List.length.{u} α xs)) -> (SlimCheck.Gen.{u} α)
-but is expected to have type
-  forall {α : Type} (xs : List.{0} α), (LT.lt.{0} Nat instLTNat (OfNat.ofNat.{0} Nat 0 (instOfNatNat 0)) (List.length.{0} α xs)) -> (SlimCheck.Gen.{0} α)
-Case conversion may be inaccurate. Consider using '#align slim_check.gen.elements SlimCheck.Gen.elementsₓ'. -/
 /-- Given a list of example generators, choose one to create an example. -/
 def elements (xs : List α) (pos : 0 < xs.length) : Gen α := do
   let ⟨⟨n, h₀, h₁⟩⟩ ← Uliftable.up <| chooseNat' 0 xs.length Pos
@@ -214,12 +190,6 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
     freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁ <;> exact ha)
 #align slim_check.gen.freq SlimCheck.Gen.freq
 
-/- warning: slim_check.gen.permutation_of -> SlimCheck.Gen.permutationOf is a dubious translation:
-lean 3 declaration is
-  forall {α : Type.{u}} (xs : List.{u} α), SlimCheck.Gen.{u} (Subtype.{succ u} (List.{u} α) (List.Perm.{u} α xs))
-but is expected to have type
-  forall {α : Type} (xs : List.{0} α), SlimCheck.Gen.{0} (Subtype.{1} (List.{0} α) (fun (ys : List.{0} α) => List.Perm.{0} α ys xs))
-Case conversion may be inaccurate. Consider using '#align slim_check.gen.permutation_of SlimCheck.Gen.permutationOfₓ'. -/
 /- ./././Mathport/Syntax/Translate/Expr.lean:177:8: unsupported: ambiguous notation -/
 /-- Generate a random permutation of a given list. -/
 def permutationOf {α : Type u} : ∀ xs : List α, Gen (Subtype <| List.Perm xs)

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

@@ -208,10 +208,7 @@ def freq (xs : List (ℕ+ × Gen α)) (pos : 0 < xs.length) : Gen α :=
   have ha : 1 ≤ s :=
     le_trans Pos <|
       List.length_map (Subtype.val ∘ Prod.fst) xs ▸
-        List.length_le_sum_of_one_le _ fun i => by
-          simp
-          intros
-          assumption
+        List.length_le_sum_of_one_le _ fun i => by simp; intros ; assumption
   have : 0 ≤ s - 1 := le_tsub_of_add_le_right ha
   Uliftable.adaptUp Gen.{0} Gen.{u} (chooseNat 0 (s - 1) this) fun i =>
     freqAux xs i.1 (by rcases i with ⟨i, h₀, h₁⟩ <;> rwa [le_tsub_iff_right] at h₁ <;> exact ha)

mathlib commit https://github.com/leanprover-community/mathlib/commit/0b9eaaa7686280fad8cce467f5c3c57ee6ce77f8

@@ -77,12 +77,16 @@ def chooseAny [Random α] : Gen α :=
 
 variable {α} [Preorder α]
 
-#print SlimCheck.Gen.choose /-
+/- warning: slim_check.gen.choose -> SlimCheck.Gen.choose is a dubious translation:
+lean 3 declaration is
+  forall {α : Type.{u1}} [_inst_1 : Preorder.{u1} α] [_inst_2 : BoundedRandom.{u1} α _inst_1] (x : α) (y : α), (LE.le.{u1} α (Preorder.toHasLe.{u1} α _inst_1) x y) -> (SlimCheck.Gen.{u1} (coeSort.{succ u1, succ (succ u1)} (Set.{u1} α) Type.{u1} (Set.hasCoeToSort.{u1} α) (Set.Icc.{u1} α _inst_1 x y)))
+but is expected to have type
+  forall (α : Type.{u1}) [_inst_1 : Preorder.{u1} α] [_inst_2 : BoundedRandom.{u1} α _inst_1] (x : α) (y : α), (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) x y) -> (SlimCheck.Gen.{u1} (Subtype.{succ u1} α (fun (a : α) => And (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) x a) (LE.le.{u1} α (Preorder.toLE.{u1} α _inst_1) a y))))
+Case conversion may be inaccurate. Consider using '#align slim_check.gen.choose SlimCheck.Gen.chooseₓ'. -/
 /-- Lift `random.random_r` to the `gen` monad. -/
 def choose [BoundedRandom α] (x y : α) (p : x ≤ y) : Gen (x .. y) :=
   ⟨fun _ => Rand.randomR x y p⟩
 #align slim_check.gen.choose SlimCheck.Gen.choose
--/
 
 end Rand
 

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

A PR accompanying #12339.

Zulip discussion

@@ -53,9 +53,9 @@ lemma chooseNatLt_aux {lo hi : Nat} (a : Nat) (h : Nat.succ lo ≤ a ∧ a ≤ h
     lo ≤ Nat.pred a ∧ Nat.pred a < hi :=
   And.intro (Nat.le_sub_one_of_lt (Nat.lt_of_succ_le h.left)) <|
     show a.pred.succ ≤ hi by
-       rw [Nat.succ_pred_eq_of_pos]
-       exact h.right
-       exact lt_of_le_of_lt (Nat.zero_le lo) h.left
+      rw [Nat.succ_pred_eq_of_pos]
+      · exact h.right
+      · exact lt_of_le_of_lt (Nat.zero_le lo) h.left
 
 /-- Generate a `Nat` example between `x` and `y` (exclusively). -/
 def chooseNatLt (lo hi : Nat) (h : lo < hi) : Gen {a // lo ≤ a ∧ a < hi} :=

Per the style guidelines, λ is disallowed in mathlib. This is close to exhaustive; I left some tactic code alone when it seemed to me that tactic could be upstreamed soon.

Notes

• In lines I was modifying anyway, I also converted => to ↦.
• Also contains some mild in-passing indentation fixes in Mathlib/Order/SupClosed.
• Some doc comments still contained Lean 3 syntax λ x, , which I also replaced.

@@ -42,12 +42,12 @@ namespace Gen
 
 /-- Lift `Random.random` to the `Gen` monad. -/
 def chooseAny (α : Type u) [Random Id α] : Gen α :=
-  λ _ => rand α
+  fun _ ↦ rand α
 
 /-- Lift `BoundedRandom.randomR` to the `Gen` monad. -/
 def choose (α : Type u) [Preorder α] [BoundedRandom Id α] (lo hi : α) (h : lo ≤ hi) :
     Gen {a // lo ≤ a ∧ a ≤ hi} :=
-  λ _ => randBound α lo hi h
+  fun _ ↦ randBound α lo hi h
 
 lemma chooseNatLt_aux {lo hi : Nat} (a : Nat) (h : Nat.succ lo ≤ a ∧ a ≤ hi) :
     lo ≤ Nat.pred a ∧ Nat.pred a < hi :=

Data.Nat.Basic is currently made of two things:

• Basic lemmas that continue the theory in Std (and could belong there, really)
• Basic algebraic order instances

I need the first ones earlier in the algebraic order hierarchy, hence the split.

Part of #9411. Similar to #9443

@@ -4,10 +4,6 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Henrik Böving, Simon Hudon
 -/
 import Mathlib.Control.Random
-import Mathlib.Control.ULiftable
-import Mathlib.Data.List.Perm
-import Mathlib.Data.Subtype
-import Mathlib.Data.Nat.Basic
 
 #align_import testing.slim_check.gen from "leanprover-community/mathlib"@"fdc286cc6967a012f41b87f76dcd2797b53152af"
 

See Zulip thread for the discussion.

@@ -97,7 +97,7 @@ def oneOf (xs : Array (Gen α)) (pos : 0 < xs.size := by decide) : Gen α := do
 /-- Given a list of examples, choose one to create an example. -/
 def elements (xs : List α) (pos : 0 < xs.length) : Gen α := do
   let ⟨x, _, h2⟩ ← ULiftable.up <| chooseNatLt 0 xs.length pos
-  pure $ xs.get ⟨x, h2⟩
+  pure <| xs.get ⟨x, h2⟩
 
 open List in
 /-- Generate a random permutation of a given list. -/

This follows the pattern that is already present in the haskell version

@@ -45,11 +45,11 @@ abbrev Gen (α : Type u) := ReaderT (ULift Nat) Rand α
 namespace Gen
 
 /-- Lift `Random.random` to the `Gen` monad. -/
-def chooseAny (α : Type u) [Random α] : Gen α :=
+def chooseAny (α : Type u) [Random Id α] : Gen α :=
   λ _ => rand α
 
 /-- Lift `BoundedRandom.randomR` to the `Gen` monad. -/
-def choose (α : Type u) [Preorder α] [BoundedRandom α] (lo hi : α) (h : lo ≤ hi) :
+def choose (α : Type u) [Preorder α] [BoundedRandom Id α] (lo hi : α) (h : lo ≤ hi) :
     Gen {a // lo ≤ a ∧ a ≤ hi} :=
   λ _ => randBound α lo hi h
 
@@ -118,7 +118,7 @@ end Gen
 
 /-- Execute a `Gen` inside the `IO` monad using `size` as the example size-/
 def Gen.run (x : Gen α) (size : Nat) : BaseIO α :=
-  IO.runRand $ ReaderT.run x ⟨size⟩
-
+  letI : MonadLift Id BaseIO := ⟨fun f => pure <| Id.run f⟩
+  IO.runRand (ReaderT.run x ⟨size⟩:)
 
 end SlimCheck

The most useful universe argument to up and down (the one in the ULift type) is now first.

Combined with the outParam, this makes using ULiftable.up more ergonomic downstream, removing a handful of type annotations.

@@ -78,7 +78,7 @@ variable {α : Type u}
 /-- Create an `Array` of examples using `x`. The size is controlled
 by the size parameter of `Gen`. -/
 def arrayOf (x : Gen α) : Gen (Array α) := do
-  let ⟨sz⟩ ← (ULiftable.up <| do choose Nat 0 (← getSize) (Nat.zero_le _) : Gen (ULift ℕ))
+  let (⟨sz⟩ : ULift ℕ) ← ULiftable.up do choose Nat 0 (← getSize) (Nat.zero_le _)
   let mut res := #[]
   for _ in [0:sz] do
     res := res.push (← x)
@@ -110,8 +110,8 @@ def permutationOf : (xs : List α) → Gen { ys // xs ~ ys }
 
 /-- Given two generators produces a tuple consisting out of the result of both -/
 def prodOf {α : Type u} {β : Type v} (x : Gen α) (y : Gen β) : Gen (α × β) := do
-  let ⟨a⟩ ← (ULiftable.up x : Gen (ULift.{max u v} α))
-  let ⟨b⟩ ← (ULiftable.up y : Gen (ULift.{max u v} β))
+  let ⟨a⟩ ← ULiftable.up.{max u v} x
+  let ⟨b⟩ ← ULiftable.up.{max u v} y
   pure (a, b)
 
 end Gen

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

@@ -78,7 +78,7 @@ variable {α : Type u}
 /-- Create an `Array` of examples using `x`. The size is controlled
 by the size parameter of `Gen`. -/
 def arrayOf (x : Gen α) : Gen (Array α) := do
-  let ⟨sz⟩ ← (ULiftable.up <| do choose Nat 0 (←getSize) (Nat.zero_le _) : Gen (ULift ℕ))
+  let ⟨sz⟩ ← (ULiftable.up <| do choose Nat 0 (← getSize) (Nat.zero_le _) : Gen (ULift ℕ))
   let mut res := #[]
   for _ in [0:sz] do
     res := res.push (← x)

@@ -55,7 +55,7 @@ def choose (α : Type u) [Preorder α] [BoundedRandom α] (lo hi : α) (h : lo 
 
 lemma chooseNatLt_aux {lo hi : Nat} (a : Nat) (h : Nat.succ lo ≤ a ∧ a ≤ hi) :
     lo ≤ Nat.pred a ∧ Nat.pred a < hi :=
-  And.intro (Nat.le_pred_of_lt (Nat.lt_of_succ_le h.left)) <|
+  And.intro (Nat.le_sub_one_of_lt (Nat.lt_of_succ_le h.left)) <|
     show a.pred.succ ≤ hi by
        rw [Nat.succ_pred_eq_of_pos]
        exact h.right

Autoimplicits are highly controversial and also defeat the performance-improving work in #6474.

The intent of this PR is to make autoImplicit opt-in on a per-file basis, by disabling it in the lakefile and enabling it again with set_option autoImplicit true in the few files that rely on it.

That also keeps this PR small, as opposed to attempting to "fix" files to not need it any more.

I claim that many of the uses of autoImplicit in these files are accidental; situations such as:

• Assuming variables are in scope, but pasting the lemma in the wrong section
• Pasting in a lemma from a scratch file without checking to see if the variable names are consistent with the rest of the file
• Making a copy-paste error between lemmas and forgetting to add an explicit arguments.

Having set_option autoImplicit false as the default prevents these types of mistake being made in the 90% of files where autoImplicits are not used at all, and causes them to be caught by CI during review.

I think there were various points during the port where we encouraged porters to delete the universes u v lines; I think having autoparams for universe variables only would cover a lot of the cases we actually use them, while avoiding any real shortcomings.

A Zulip poll (after combining overlapping votes accordingly) was in favor of this change with 5:5:18 as the no:dontcare:yes vote ratio.

While this PR was being reviewed, a handful of files gained some more likely-accidental autoImplicits. In these places, set_option autoImplicit true has been placed locally within a section, rather than at the top of the file.

@@ -31,6 +31,8 @@ random testing
 * https://hackage.haskell.org/package/QuickCheck
 -/
 
+set_option autoImplicit true
+
 namespace SlimCheck
 
 open Random

• depends on: #5966

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

@@ -2,11 +2,6 @@
 Copyright (c) 2021 Henrik Böving. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Henrik Böving, Simon Hudon
-
-! This file was ported from Lean 3 source module testing.slim_check.gen
-! leanprover-community/mathlib commit fdc286cc6967a012f41b87f76dcd2797b53152af
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Control.Random
 import Mathlib.Control.ULiftable
@@ -14,6 +9,8 @@ import Mathlib.Data.List.Perm
 import Mathlib.Data.Subtype
 import Mathlib.Data.Nat.Basic
 
+#align_import testing.slim_check.gen from "leanprover-community/mathlib"@"fdc286cc6967a012f41b87f76dcd2797b53152af"
+
 /-!
 # `Gen` Monad
 

The use of auto-implicits was introducing a universe metavariable where we wanted a free variable.

The new ULiftable instances handle the common case of a universe polymorphic monad with a universe-lifted state from Type.

@@ -9,6 +9,7 @@ Authors: Henrik Böving, Simon Hudon
 ! if you have ported upstream changes.
 -/
 import Mathlib.Control.Random
+import Mathlib.Control.ULiftable
 import Mathlib.Data.List.Perm
 import Mathlib.Data.Subtype
 import Mathlib.Data.Nat.Basic
@@ -73,10 +74,12 @@ def getSize : Gen Nat :=
 def resize (f : Nat → Nat) (x : Gen α) : Gen α :=
   withReader (ULift.up ∘ f ∘ ULift.down) x
 
+variable {α : Type u}
+
 /-- Create an `Array` of examples using `x`. The size is controlled
 by the size parameter of `Gen`. -/
 def arrayOf (x : Gen α) : Gen (Array α) := do
-  let sz ← choose Nat 0 (←getSize) (Nat.zero_le _)
+  let ⟨sz⟩ ← (ULiftable.up <| do choose Nat 0 (←getSize) (Nat.zero_le _) : Gen (ULift ℕ))
   let mut res := #[]
   for _ in [0:sz] do
     res := res.push (← x)
@@ -89,26 +92,28 @@ def listOf (x : Gen α) : Gen (List α) :=
 
 /-- Given a list of example generators, choose one to create an example. -/
 def oneOf (xs : Array (Gen α)) (pos : 0 < xs.size := by decide) : Gen α := do
-  let ⟨x, _, h2⟩ ← chooseNatLt 0 xs.size pos
+  let ⟨x, _, h2⟩ ← ULiftable.up <| chooseNatLt 0 xs.size pos
   xs.get ⟨x, h2⟩
 
 /-- Given a list of examples, choose one to create an example. -/
 def elements (xs : List α) (pos : 0 < xs.length) : Gen α := do
-  let ⟨x, _, h2⟩ ← chooseNatLt 0 xs.length pos
+  let ⟨x, _, h2⟩ ← ULiftable.up <| chooseNatLt 0 xs.length pos
   pure $ xs.get ⟨x, h2⟩
 
 open List in
 /-- Generate a random permutation of a given list. -/
-def permutationOf : (xs : List α) → Gen { ys // ys ~ xs }
+def permutationOf : (xs : List α) → Gen { ys // xs ~ ys }
   | [] => pure ⟨[], Perm.nil⟩
   | x::xs => do
     let ⟨ys, h1⟩ ← permutationOf xs
-    let ⟨n, _, h3⟩ ← choose Nat 0 ys.length (Nat.zero_le _)
-    pure ⟨insertNth n x ys, Perm.trans (perm_insertNth _ _ h3) (Perm.cons _ h1)⟩
+    let ⟨n, _, h3⟩ ← ULiftable.up <| choose Nat 0 ys.length (Nat.zero_le _)
+    pure ⟨insertNth n x ys, Perm.trans (Perm.cons _ h1) (perm_insertNth _ _ h3).symm⟩
 
 /-- Given two generators produces a tuple consisting out of the result of both -/
-def prodOf {α β : Type u} (x : Gen α) (y : Gen β) : Gen (α × β) := do
-  pure (←x, ←y)
+def prodOf {α : Type u} {β : Type v} (x : Gen α) (y : Gen β) : Gen (α × β) := do
+  let ⟨a⟩ ← (ULiftable.up x : Gen (ULift.{max u v} α))
+  let ⟨b⟩ ← (ULiftable.up y : Gen (ULift.{max u v} β))
+  pure (a, b)
 
 end Gen
 

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

@@ -3,7 +3,7 @@ Copyright (c) 2021 Henrik Böving. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Henrik Böving, Simon Hudon
 
-! This file was ported from Lean 3 source module testing.slim_check.testable
+! This file was ported from Lean 3 source module testing.slim_check.gen
 ! leanprover-community/mathlib commit fdc286cc6967a012f41b87f76dcd2797b53152af
 ! Please do not edit these lines, except to modify the commit id
 ! if you have ported upstream changes.