@@ -4,7 +4,11 @@ Released under Apache 2.0 license as described in the file LICENSE.
4
4
Authors: Leonardo de Moura, Jeremy Avigad, Minchao Wu, Mario Carneiro
5
5
-/
6
6
import Mathlib.Data.Fin.Basic
7
- import Mathlib.Data.Finset.Basic
7
+ import Mathlib.Data.Finset.Attach
8
+ import Mathlib.Data.Finset.Disjoint
9
+ import Mathlib.Data.Finset.Erase
10
+ import Mathlib.Data.Finset.Filter
11
+ import Mathlib.Data.Finset.Range
8
12
import Mathlib.Data.Finset.SymmDiff
9
13
10
14
/-! # Image and map operations on finite sets
@@ -398,11 +402,6 @@ theorem filter_image {p : β → Prop} [DecidablePred p] :
398
402
⟨by rintro ⟨⟨x, h1, rfl⟩, h2⟩; exact ⟨x, ⟨h1, h2⟩, rfl⟩,
399
403
by rintro ⟨x, ⟨h1, h2⟩, rfl⟩; exact ⟨⟨x, h1, rfl⟩, h2⟩⟩
400
404
401
- @[deprecated filter_mem_eq_inter (since := "2024-09-15")]
402
- theorem filter_mem_image_eq_image (f : α → β) (s : Finset α) (t : Finset β) (h : ∀ x ∈ s, f x ∈ t) :
403
- (t.filter fun y => y ∈ s.image f) = s.image f := by
404
- rwa [filter_mem_eq_inter, inter_eq_right, image_subset_iff]
405
-
406
405
theorem fiber_nonempty_iff_mem_image {y : β} : (s.filter (f · = y)).Nonempty ↔ y ∈ s.image f := by
407
406
simp [Finset.Nonempty]
408
407
0 commit comments