direct_sum_is_internal ⟷ Counterexamples.DirectSumIsInternal

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

@@ -92,11 +92,11 @@ theorem withSign.not_injective :
     DirectSum.lof ℕ _ (fun i => with_sign i) 1 p1 + DirectSum.lof ℕ _ (fun i => with_sign i) (-1) n1
   have : z ≠ 0 := by
     intro h
-    dsimp [z, DirectSum.lof_eq_of, DirectSum.of] at h 
+    dsimp [z, DirectSum.lof_eq_of, DirectSum.of] at h
     replace h := dfinsupp.ext_iff.mp h 1
     rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne units_int.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
-      Submodule.coe_zero] at h 
+      Submodule.coe_zero] at h
     apply zero_ne_one h.symm
   apply hinj.ne this
   rw [LinearMap.map_zero, LinearMap.map_add, DirectSum.toModule_lof, DirectSum.toModule_lof]

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

@@ -3,9 +3,9 @@ Copyright (c) 2021 Eric Wieser. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Eric Wieser, Kevin Buzzard
 -/
-import Mathbin.Algebra.DirectSum.Module
-import Mathbin.Algebra.Group.ConjFinite
-import Mathbin.Tactic.FinCases
+import Algebra.DirectSum.Module
+import Algebra.Group.ConjFinite
+import Tactic.FinCases
 
 #align_import direct_sum_is_internal from "leanprover-community/mathlib"@"08b081ea92d80e3a41f899eea36ef6d56e0f1db0"
 

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

@@ -2,16 +2,13 @@
 Copyright (c) 2021 Eric Wieser. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Eric Wieser, Kevin Buzzard
-
-! This file was ported from Lean 3 source module direct_sum_is_internal
-! leanprover-community/mathlib commit 08b081ea92d80e3a41f899eea36ef6d56e0f1db0
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathbin.Algebra.DirectSum.Module
 import Mathbin.Algebra.Group.ConjFinite
 import Mathbin.Tactic.FinCases
 
+#align_import direct_sum_is_internal from "leanprover-community/mathlib"@"08b081ea92d80e3a41f899eea36ef6d56e0f1db0"
+
 /-!
 # Not all complementary decompositions of a module over a semiring make up a direct sum
 

mathlib commit https://github.com/leanprover-community/mathlib/commit/bf2428c9486c407ca38b5b3fb10b87dad0bc99fa

@@ -4,7 +4,7 @@ Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Eric Wieser, Kevin Buzzard
 
 ! This file was ported from Lean 3 source module direct_sum_is_internal
-! leanprover-community/mathlib commit 328375597f2c0dd00522d9c2e5a33b6a6128feeb
+! leanprover-community/mathlib commit 08b081ea92d80e3a41f899eea36ef6d56e0f1db0
 ! 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.FinCases
 /-!
 # Not all complementary decompositions of a module over a semiring make up a direct sum
 
+> THIS FILE IS SYNCHRONIZED WITH MATHLIB4.
+> Any changes to this file require a corresponding PR to mathlib4.
+
 This shows that while `ℤ≤0` and `ℤ≥0` are complementary `ℕ`-submodules of `ℤ`, which in turn
 implies as a collection they are `complete_lattice.independent` and that they span all of `ℤ`, they
 do not form a decomposition into a direct sum.

mathlib commit https://github.com/leanprover-community/mathlib/commit/4e24c4bfcff371c71f7ba22050308aa17815626c

@@ -94,8 +94,8 @@ theorem withSign.not_injective :
     intro h
     dsimp [z, DirectSum.lof_eq_of, DirectSum.of] at h 
     replace h := dfinsupp.ext_iff.mp h 1
-    rw [Dfinsupp.zero_apply, Dfinsupp.add_apply, Dfinsupp.single_eq_same,
-      Dfinsupp.single_eq_of_ne units_int.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
+    rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
+      DFinsupp.single_eq_of_ne units_int.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h 
     apply zero_ne_one h.symm
   apply hinj.ne this

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

@@ -41,10 +41,8 @@ def withSign (i : ℤˣ) : Submodule ℕ ℤ :=
             exact add_nonneg hx hy }
 #align counterexample.with_sign Counterexample.withSign
 
--- mathport name: «exprℤ≥0»
 local notation "ℤ≥0" => withSign 1
 
--- mathport name: «exprℤ≤0»
 local notation "ℤ≤0" => withSign (-1)
 
 theorem mem_withSign_one {x : ℤ} : x ∈ ℤ≥0 ↔ 0 ≤ x :=

mathlib commit https://github.com/leanprover-community/mathlib/commit/a3209ddf94136d36e5e5c624b10b2a347cc9d090

A PR accompanying #12339.

Zulip discussion

@@ -60,8 +60,8 @@ theorem withSign.isCompl : IsCompl ℤ≥0 ℤ≤0 := by
   · rw [codisjoint_iff_le_sup]
     intro x _hx
     obtain hp | hn := (le_refl (0 : ℤ)).le_or_le x
-    exact Submodule.mem_sup_left (mem_withSign_one.mpr hp)
-    exact Submodule.mem_sup_right (mem_withSign_neg_one.mpr hn)
+    · exact Submodule.mem_sup_left (mem_withSign_one.mpr hp)
+    · exact Submodule.mem_sup_right (mem_withSign_neg_one.mpr hn)
 #align counterexample.with_sign.is_compl Counterexample.withSign.isCompl
 
 def withSign.independent : CompleteLattice.Independent withSign := by

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

@@ -86,8 +86,6 @@ theorem withSign.not_injective :
     DirectSum.lof ℕ _ (fun i => withSign i) 1 p1 + DirectSum.lof ℕ _ (fun i => withSign i) (-1) n1
   have : z ≠ 0 := by
     intro h
-    -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
-    dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
     replace h := DFunLike.congr_fun h 1
     -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
     erw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,

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>

@@ -5,6 +5,7 @@ Authors: Eric Wieser, Kevin Buzzard
 -/
 import Mathlib.Algebra.DirectSum.Module
 import Mathlib.Algebra.Group.ConjFinite
+import Mathlib.Data.Fintype.Lattice
 import Mathlib.Tactic.FinCases
 
 #align_import direct_sum_is_internal from "leanprover-community/mathlib"@"328375597f2c0dd00522d9c2e5a33b6a6128feeb"

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>

@@ -87,7 +87,7 @@ theorem withSign.not_injective :
     intro h
     -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
     dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
-    replace h := FunLike.congr_fun h 1
+    replace h := DFunLike.congr_fun h 1
     -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
     erw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,

This reverts commit f3695eb2.

@@ -88,7 +88,8 @@ theorem withSign.not_injective :
     -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
     dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
     replace h := FunLike.congr_fun h 1
-    rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
+    -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
+    erw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h
     apply zero_ne_one h.symm

This reverts commit 26eb2b0a.

@@ -88,8 +88,7 @@ theorem withSign.not_injective :
     -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
     dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
     replace h := FunLike.congr_fun h 1
-    -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
-    erw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
+    rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h
     apply zero_ne_one h.symm

This includes all the changes from #7606.

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

@@ -88,7 +88,8 @@ theorem withSign.not_injective :
     -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
     dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
     replace h := FunLike.congr_fun h 1
-    rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
+    -- This used to be `rw`, but we need `erw` after leanprover/lean4#2644
+    erw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h
     apply zero_ne_one h.symm

@eric-wieser, would you be able to find a better solution to this?

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

@@ -87,7 +87,7 @@ theorem withSign.not_injective :
     intro h
     -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
     dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
-    replace h := DFinsupp.ext_iff.mp h 1
+    replace h := FunLike.congr_fun h 1
     rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
       DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h

• depends on: #5966

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

@@ -2,16 +2,13 @@
 Copyright (c) 2021 Eric Wieser. All rights reserved.
 Released under Apache 2.0 license as described in the file LICENSE.
 Authors: Eric Wieser, Kevin Buzzard
-
-! This file was ported from Lean 3 source module direct_sum_is_internal
-! leanprover-community/mathlib commit 328375597f2c0dd00522d9c2e5a33b6a6128feeb
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
 -/
 import Mathlib.Algebra.DirectSum.Module
 import Mathlib.Algebra.Group.ConjFinite
 import Mathlib.Tactic.FinCases
 
+#align_import direct_sum_is_internal from "leanprover-community/mathlib"@"328375597f2c0dd00522d9c2e5a33b6a6128feeb"
+
 /-!
 # Not all complementary decompositions of a module over a semiring make up a direct sum
 

See #4354

@@ -88,11 +88,11 @@ theorem withSign.not_injective :
     DirectSum.lof ℕ _ (fun i => withSign i) 1 p1 + DirectSum.lof ℕ _ (fun i => withSign i) (-1) n1
   have : z ≠ 0 := by
     intro h
-    -- porting note: `Dfinsupp.singleAddHom_apply` doesn't work so we have to unfold
-    dsimp [DirectSum.lof_eq_of, DirectSum.of, Dfinsupp.singleAddHom] at h
-    replace h := Dfinsupp.ext_iff.mp h 1
-    rw [Dfinsupp.zero_apply, Dfinsupp.add_apply, Dfinsupp.single_eq_same,
-      Dfinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
+    -- porting note: `DFinsupp.singleAddHom_apply` doesn't work so we have to unfold
+    dsimp [DirectSum.lof_eq_of, DirectSum.of, DFinsupp.singleAddHom] at h
+    replace h := DFinsupp.ext_iff.mp h 1
+    rw [DFinsupp.zero_apply, DFinsupp.add_apply, DFinsupp.single_eq_same,
+      DFinsupp.single_eq_of_ne UnitsInt.one_ne_neg_one.symm, add_zero, Subtype.ext_iff,
       Submodule.coe_zero] at h
     apply zero_ne_one h.symm
   apply hinj.ne this