combinatorics.set_family.kleitman ⟷
Mathlib.Combinatorics.SetFamily.Kleitman
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.
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mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83
@@ -74,7 +74,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
rw [union_sdiff_left, sdiff_eq_inter_compl]
refine' le_of_mul_le_mul_left _ (pow_pos zero_lt_two <| card α + 1)
- rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
+ rw [pow_succ, mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
refine'
(add_le_add
((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
@@ -95,7 +95,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
(hf₁ _ <| subset_cons _ hi).2.2)
_).trans
_
- rw [mul_tsub, two_mul, ← pow_succ, ←
+ rw [mul_tsub, two_mul, ← pow_succ', ←
add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83
@@ -53,6 +53,51 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
induction' s using Finset.cons_induction with i s hi ih generalizing f
· simp
classical
+ set f' : ι → Finset (Finset α) := fun j =>
+ if hj : j ∈ cons i s hi then (hf j hj).exists_card_eq.some else ∅ with hf'
+ have hf₁ :
+ ∀ j,
+ j ∈ cons i s hi →
+ f j ⊆ f' j ∧ 2 * (f' j).card = 2 ^ card α ∧ (f' j : Set (Finset α)).Intersecting :=
+ by
+ rintro j hj
+ simp_rw [hf', dif_pos hj, ← Fintype.card_finset]
+ exact Classical.choose_spec (hf j hj).exists_card_eq
+ have hf₂ : ∀ j, j ∈ cons i s hi → IsUpperSet (f' j : Set (Finset α)) :=
+ by
+ refine' fun j hj => (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
+ rw [Fintype.card_finset]
+ exact (hf₁ _ hj).2.1
+ refine' (card_le_of_subset <| bUnion_mono fun j hj => (hf₁ _ hj).1).trans _
+ nth_rw 1 [cons_eq_insert i]
+ rw [bUnion_insert]
+ refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
+ rw [union_sdiff_left, sdiff_eq_inter_compl]
+ refine' le_of_mul_le_mul_left _ (pow_pos zero_lt_two <| card α + 1)
+ rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
+ refine'
+ (add_le_add
+ ((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
+ (hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
+ (mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans
+ _
+ · rw [coe_bUnion]
+ exact isUpperSet_iUnion₂ fun i hi => hf₂ _ <| subset_cons _ hi
+ · rw [coe_compl]
+ exact (hf₂ _ <| mem_cons_self _ _).compl
+ rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
+ (hf₁ _ <| mem_cons_self _ _).2.1, two_mul, add_tsub_cancel_left, ← mul_tsub, ← mul_two,
+ mul_assoc, ← add_mul, mul_comm]
+ refine' mul_le_mul_left' _ _
+ refine'
+ (add_le_add_left
+ (ih ((card_le_of_subset <| subset_cons _).trans hs) _ fun i hi =>
+ (hf₁ _ <| subset_cons _ hi).2.2)
+ _).trans
+ _
+ rw [mul_tsub, two_mul, ← pow_succ, ←
+ add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
+ tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
-/
mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83
@@ -53,51 +53,6 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
induction' s using Finset.cons_induction with i s hi ih generalizing f
· simp
classical
- set f' : ι → Finset (Finset α) := fun j =>
- if hj : j ∈ cons i s hi then (hf j hj).exists_card_eq.some else ∅ with hf'
- have hf₁ :
- ∀ j,
- j ∈ cons i s hi →
- f j ⊆ f' j ∧ 2 * (f' j).card = 2 ^ card α ∧ (f' j : Set (Finset α)).Intersecting :=
- by
- rintro j hj
- simp_rw [hf', dif_pos hj, ← Fintype.card_finset]
- exact Classical.choose_spec (hf j hj).exists_card_eq
- have hf₂ : ∀ j, j ∈ cons i s hi → IsUpperSet (f' j : Set (Finset α)) :=
- by
- refine' fun j hj => (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
- rw [Fintype.card_finset]
- exact (hf₁ _ hj).2.1
- refine' (card_le_of_subset <| bUnion_mono fun j hj => (hf₁ _ hj).1).trans _
- nth_rw 1 [cons_eq_insert i]
- rw [bUnion_insert]
- refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
- rw [union_sdiff_left, sdiff_eq_inter_compl]
- refine' le_of_mul_le_mul_left _ (pow_pos zero_lt_two <| card α + 1)
- rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
- refine'
- (add_le_add
- ((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
- (hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
- (mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans
- _
- · rw [coe_bUnion]
- exact isUpperSet_iUnion₂ fun i hi => hf₂ _ <| subset_cons _ hi
- · rw [coe_compl]
- exact (hf₂ _ <| mem_cons_self _ _).compl
- rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
- (hf₁ _ <| mem_cons_self _ _).2.1, two_mul, add_tsub_cancel_left, ← mul_tsub, ← mul_two,
- mul_assoc, ← add_mul, mul_comm]
- refine' mul_le_mul_left' _ _
- refine'
- (add_le_add_left
- (ih ((card_le_of_subset <| subset_cons _).trans hs) _ fun i hi =>
- (hf₁ _ <| subset_cons _ hi).2.2)
- _).trans
- _
- rw [mul_tsub, two_mul, ← pow_succ, ←
- add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
- tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
-/
mathlib commit https://github.com/leanprover-community/mathlib/commit/65a1391a0106c9204fe45bc73a039f056558cb83
@@ -96,7 +96,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
_).trans
_
rw [mul_tsub, two_mul, ← pow_succ, ←
- add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
+ add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
-/
mathlib commit https://github.com/leanprover-community/mathlib/commit/ce64cd319bb6b3e82f31c2d38e79080d377be451
@@ -3,8 +3,8 @@ Copyright (c) 2022 Yaël Dillies. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Yaël Dillies
-/
-import Mathbin.Combinatorics.SetFamily.HarrisKleitman
-import Mathbin.Combinatorics.SetFamily.Intersecting
+import Combinatorics.SetFamily.HarrisKleitman
+import Combinatorics.SetFamily.Intersecting
#align_import combinatorics.set_family.kleitman from "leanprover-community/mathlib"@"50832daea47b195a48b5b33b1c8b2162c48c3afc"
mathlib commit https://github.com/leanprover-community/mathlib/commit/8ea5598db6caeddde6cb734aa179cc2408dbd345
@@ -2,15 +2,12 @@
Copyright (c) 2022 Yaël Dillies. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Yaël Dillies
-
-! This file was ported from Lean 3 source module combinatorics.set_family.kleitman
-! leanprover-community/mathlib commit 50832daea47b195a48b5b33b1c8b2162c48c3afc
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
-/
import Mathbin.Combinatorics.SetFamily.HarrisKleitman
import Mathbin.Combinatorics.SetFamily.Intersecting
+#align_import combinatorics.set_family.kleitman from "leanprover-community/mathlib"@"50832daea47b195a48b5b33b1c8b2162c48c3afc"
+
/-!
# Kleitman's bound on the size of intersecting families
mathlib commit https://github.com/leanprover-community/mathlib/commit/9fb8964792b4237dac6200193a0d533f1b3f7423
@@ -38,6 +38,7 @@ open Fintype (card)
variable {ι α : Type _} [Fintype α] [DecidableEq α] [Nonempty α]
+#print Finset.card_biUnion_le_of_intersecting /-
/-- **Kleitman's theorem**. An intersecting family on `n` elements contains at most `2ⁿ⁻¹` sets, and
each further intersecting family takes at most half of the sets that are in no previous family. -/
theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
@@ -101,4 +102,5 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
+-/
mathlib commit https://github.com/leanprover-community/mathlib/commit/5f25c089cb34db4db112556f23c50d12da81b297
@@ -55,50 +55,50 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
induction' s using Finset.cons_induction with i s hi ih generalizing f
· simp
classical
- set f' : ι → Finset (Finset α) := fun j =>
- if hj : j ∈ cons i s hi then (hf j hj).exists_card_eq.some else ∅ with hf'
- have hf₁ :
- ∀ j,
- j ∈ cons i s hi →
- f j ⊆ f' j ∧ 2 * (f' j).card = 2 ^ card α ∧ (f' j : Set (Finset α)).Intersecting :=
- by
- rintro j hj
- simp_rw [hf', dif_pos hj, ← Fintype.card_finset]
- exact Classical.choose_spec (hf j hj).exists_card_eq
- have hf₂ : ∀ j, j ∈ cons i s hi → IsUpperSet (f' j : Set (Finset α)) :=
- by
- refine' fun j hj => (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
- rw [Fintype.card_finset]
- exact (hf₁ _ hj).2.1
- refine' (card_le_of_subset <| bUnion_mono fun j hj => (hf₁ _ hj).1).trans _
- nth_rw 1 [cons_eq_insert i]
- rw [bUnion_insert]
- refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
- rw [union_sdiff_left, sdiff_eq_inter_compl]
- refine' le_of_mul_le_mul_left _ (pow_pos zero_lt_two <| card α + 1)
- rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
- refine'
- (add_le_add
- ((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
- (hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
- (mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans
- _
- · rw [coe_bUnion]
- exact isUpperSet_iUnion₂ fun i hi => hf₂ _ <| subset_cons _ hi
- · rw [coe_compl]
- exact (hf₂ _ <| mem_cons_self _ _).compl
- rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
- (hf₁ _ <| mem_cons_self _ _).2.1, two_mul, add_tsub_cancel_left, ← mul_tsub, ← mul_two,
- mul_assoc, ← add_mul, mul_comm]
- refine' mul_le_mul_left' _ _
- refine'
- (add_le_add_left
- (ih ((card_le_of_subset <| subset_cons _).trans hs) _ fun i hi =>
- (hf₁ _ <| subset_cons _ hi).2.2)
- _).trans
- _
- rw [mul_tsub, two_mul, ← pow_succ, ←
- add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
- tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
+ set f' : ι → Finset (Finset α) := fun j =>
+ if hj : j ∈ cons i s hi then (hf j hj).exists_card_eq.some else ∅ with hf'
+ have hf₁ :
+ ∀ j,
+ j ∈ cons i s hi →
+ f j ⊆ f' j ∧ 2 * (f' j).card = 2 ^ card α ∧ (f' j : Set (Finset α)).Intersecting :=
+ by
+ rintro j hj
+ simp_rw [hf', dif_pos hj, ← Fintype.card_finset]
+ exact Classical.choose_spec (hf j hj).exists_card_eq
+ have hf₂ : ∀ j, j ∈ cons i s hi → IsUpperSet (f' j : Set (Finset α)) :=
+ by
+ refine' fun j hj => (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
+ rw [Fintype.card_finset]
+ exact (hf₁ _ hj).2.1
+ refine' (card_le_of_subset <| bUnion_mono fun j hj => (hf₁ _ hj).1).trans _
+ nth_rw 1 [cons_eq_insert i]
+ rw [bUnion_insert]
+ refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
+ rw [union_sdiff_left, sdiff_eq_inter_compl]
+ refine' le_of_mul_le_mul_left _ (pow_pos zero_lt_two <| card α + 1)
+ rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
+ refine'
+ (add_le_add
+ ((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
+ (hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
+ (mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans
+ _
+ · rw [coe_bUnion]
+ exact isUpperSet_iUnion₂ fun i hi => hf₂ _ <| subset_cons _ hi
+ · rw [coe_compl]
+ exact (hf₂ _ <| mem_cons_self _ _).compl
+ rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
+ (hf₁ _ <| mem_cons_self _ _).2.1, two_mul, add_tsub_cancel_left, ← mul_tsub, ← mul_two,
+ mul_assoc, ← add_mul, mul_comm]
+ refine' mul_le_mul_left' _ _
+ refine'
+ (add_le_add_left
+ (ih ((card_le_of_subset <| subset_cons _).trans hs) _ fun i hi =>
+ (hf₁ _ <| subset_cons _ hi).2.2)
+ _).trans
+ _
+ rw [mul_tsub, two_mul, ← pow_succ, ←
+ add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
+ tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
mathlib commit https://github.com/leanprover-community/mathlib/commit/917c3c072e487b3cccdbfeff17e75b40e45f66cb
@@ -38,12 +38,6 @@ open Fintype (card)
variable {ι α : Type _} [Fintype α] [DecidableEq α] [Nonempty α]
-/- warning: finset.card_bUnion_le_of_intersecting -> Finset.card_biUnion_le_of_intersecting is a dubious translation:
-lean 3 declaration is
- forall {ι : Type.{u1}} {α : Type.{u2}} [_inst_1 : Fintype.{u2} α] [_inst_2 : DecidableEq.{succ u2} α] [_inst_3 : Nonempty.{succ u2} α] (s : Finset.{u1} ι) (f : ι -> (Finset.{u2} (Finset.{u2} α))), (forall (i : ι), (Membership.Mem.{u1, u1} ι (Finset.{u1} ι) (Finset.hasMem.{u1} ι) i s) -> (Set.Intersecting.{u2} (Finset.{u2} α) (Lattice.toSemilatticeInf.{u2} (Finset.{u2} α) (Finset.lattice.{u2} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.orderBot.{u2} α) ((fun (a : Type.{u2}) (b : Type.{u2}) [self : HasLiftT.{succ u2, succ u2} a b] => self.0) (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (HasLiftT.mk.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (CoeTCₓ.coe.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (Finset.Set.hasCoeT.{u2} (Finset.{u2} α)))) (f i)))) -> (LE.le.{0} Nat Nat.hasLe (Finset.card.{u2} (Finset.{u2} α) (Finset.biUnion.{u1, u2} ι (Finset.{u2} α) (fun (a : Finset.{u2} α) (b : Finset.{u2} α) => Finset.decidableEq.{u2} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (Fintype.card.{u2} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (Fintype.card.{u2} α _inst_1) (Finset.card.{u1} ι s)))))
-but is expected to have type
- forall {ι : Type.{u2}} {α : Type.{u1}} [_inst_1 : Fintype.{u1} α] [_inst_2 : DecidableEq.{succ u1} α] [_inst_3 : Nonempty.{succ u1} α] (s : Finset.{u2} ι) (f : ι -> (Finset.{u1} (Finset.{u1} α))), (forall (i : ι), (Membership.mem.{u2, u2} ι (Finset.{u2} ι) (Finset.instMembershipFinset.{u2} ι) i s) -> (Set.Intersecting.{u1} (Finset.{u1} α) (Lattice.toSemilatticeInf.{u1} (Finset.{u1} α) (Finset.instLatticeFinset.{u1} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.instOrderBotFinsetToLEToPreorderPartialOrder.{u1} α) (Finset.toSet.{u1} (Finset.{u1} α) (f i)))) -> (LE.le.{0} Nat instLENat (Finset.card.{u1} (Finset.{u1} α) (Finset.biUnion.{u2, u1} ι (Finset.{u1} α) (fun (a : Finset.{u1} α) (b : Finset.{u1} α) => Finset.decidableEq.{u1} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (Fintype.card.{u1} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (Fintype.card.{u1} α _inst_1) (Finset.card.{u2} ι s)))))
-Case conversion may be inaccurate. Consider using '#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersectingₓ'. -/
/-- **Kleitman's theorem**. An intersecting family on `n` elements contains at most `2ⁿ⁻¹` sets, and
each further intersecting family takes at most half of the sets that are in no previous family. -/
theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
mathlib commit https://github.com/leanprover-community/mathlib/commit/e3fb84046afd187b710170887195d50bada934ee
@@ -38,17 +38,17 @@ open Fintype (card)
variable {ι α : Type _} [Fintype α] [DecidableEq α] [Nonempty α]
-/- warning: finset.card_bUnion_le_of_intersecting -> Finset.card_bunionᵢ_le_of_intersecting is a dubious translation:
+/- warning: finset.card_bUnion_le_of_intersecting -> Finset.card_biUnion_le_of_intersecting is a dubious translation:
lean 3 declaration is
- forall {ι : Type.{u1}} {α : Type.{u2}} [_inst_1 : Fintype.{u2} α] [_inst_2 : DecidableEq.{succ u2} α] [_inst_3 : Nonempty.{succ u2} α] (s : Finset.{u1} ι) (f : ι -> (Finset.{u2} (Finset.{u2} α))), (forall (i : ι), (Membership.Mem.{u1, u1} ι (Finset.{u1} ι) (Finset.hasMem.{u1} ι) i s) -> (Set.Intersecting.{u2} (Finset.{u2} α) (Lattice.toSemilatticeInf.{u2} (Finset.{u2} α) (Finset.lattice.{u2} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.orderBot.{u2} α) ((fun (a : Type.{u2}) (b : Type.{u2}) [self : HasLiftT.{succ u2, succ u2} a b] => self.0) (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (HasLiftT.mk.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (CoeTCₓ.coe.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (Finset.Set.hasCoeT.{u2} (Finset.{u2} α)))) (f i)))) -> (LE.le.{0} Nat Nat.hasLe (Finset.card.{u2} (Finset.{u2} α) (Finset.bunionᵢ.{u1, u2} ι (Finset.{u2} α) (fun (a : Finset.{u2} α) (b : Finset.{u2} α) => Finset.decidableEq.{u2} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (Fintype.card.{u2} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (Fintype.card.{u2} α _inst_1) (Finset.card.{u1} ι s)))))
+ forall {ι : Type.{u1}} {α : Type.{u2}} [_inst_1 : Fintype.{u2} α] [_inst_2 : DecidableEq.{succ u2} α] [_inst_3 : Nonempty.{succ u2} α] (s : Finset.{u1} ι) (f : ι -> (Finset.{u2} (Finset.{u2} α))), (forall (i : ι), (Membership.Mem.{u1, u1} ι (Finset.{u1} ι) (Finset.hasMem.{u1} ι) i s) -> (Set.Intersecting.{u2} (Finset.{u2} α) (Lattice.toSemilatticeInf.{u2} (Finset.{u2} α) (Finset.lattice.{u2} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.orderBot.{u2} α) ((fun (a : Type.{u2}) (b : Type.{u2}) [self : HasLiftT.{succ u2, succ u2} a b] => self.0) (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (HasLiftT.mk.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (CoeTCₓ.coe.{succ u2, succ u2} (Finset.{u2} (Finset.{u2} α)) (Set.{u2} (Finset.{u2} α)) (Finset.Set.hasCoeT.{u2} (Finset.{u2} α)))) (f i)))) -> (LE.le.{0} Nat Nat.hasLe (Finset.card.{u2} (Finset.{u2} α) (Finset.biUnion.{u1, u2} ι (Finset.{u2} α) (fun (a : Finset.{u2} α) (b : Finset.{u2} α) => Finset.decidableEq.{u2} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (Fintype.card.{u2} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat (Monoid.Pow.{0} Nat Nat.monoid)) (OfNat.ofNat.{0} Nat 2 (OfNat.mk.{0} Nat 2 (bit0.{0} Nat Nat.hasAdd (One.one.{0} Nat Nat.hasOne)))) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat Nat.hasSub) (Fintype.card.{u2} α _inst_1) (Finset.card.{u1} ι s)))))
but is expected to have type
- forall {ι : Type.{u2}} {α : Type.{u1}} [_inst_1 : Fintype.{u1} α] [_inst_2 : DecidableEq.{succ u1} α] [_inst_3 : Nonempty.{succ u1} α] (s : Finset.{u2} ι) (f : ι -> (Finset.{u1} (Finset.{u1} α))), (forall (i : ι), (Membership.mem.{u2, u2} ι (Finset.{u2} ι) (Finset.instMembershipFinset.{u2} ι) i s) -> (Set.Intersecting.{u1} (Finset.{u1} α) (Lattice.toSemilatticeInf.{u1} (Finset.{u1} α) (Finset.instLatticeFinset.{u1} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.instOrderBotFinsetToLEToPreorderPartialOrder.{u1} α) (Finset.toSet.{u1} (Finset.{u1} α) (f i)))) -> (LE.le.{0} Nat instLENat (Finset.card.{u1} (Finset.{u1} α) (Finset.bunionᵢ.{u2, u1} ι (Finset.{u1} α) (fun (a : Finset.{u1} α) (b : Finset.{u1} α) => Finset.decidableEq.{u1} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (Fintype.card.{u1} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (Fintype.card.{u1} α _inst_1) (Finset.card.{u2} ι s)))))
-Case conversion may be inaccurate. Consider using '#align finset.card_bUnion_le_of_intersecting Finset.card_bunionᵢ_le_of_intersectingₓ'. -/
+ forall {ι : Type.{u2}} {α : Type.{u1}} [_inst_1 : Fintype.{u1} α] [_inst_2 : DecidableEq.{succ u1} α] [_inst_3 : Nonempty.{succ u1} α] (s : Finset.{u2} ι) (f : ι -> (Finset.{u1} (Finset.{u1} α))), (forall (i : ι), (Membership.mem.{u2, u2} ι (Finset.{u2} ι) (Finset.instMembershipFinset.{u2} ι) i s) -> (Set.Intersecting.{u1} (Finset.{u1} α) (Lattice.toSemilatticeInf.{u1} (Finset.{u1} α) (Finset.instLatticeFinset.{u1} α (fun (a : α) (b : α) => _inst_2 a b))) (Finset.instOrderBotFinsetToLEToPreorderPartialOrder.{u1} α) (Finset.toSet.{u1} (Finset.{u1} α) (f i)))) -> (LE.le.{0} Nat instLENat (Finset.card.{u1} (Finset.{u1} α) (Finset.biUnion.{u2, u1} ι (Finset.{u1} α) (fun (a : Finset.{u1} α) (b : Finset.{u1} α) => Finset.decidableEq.{u1} α (fun (a : α) (b : α) => _inst_2 a b) a b) s f)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (Fintype.card.{u1} α _inst_1)) (HPow.hPow.{0, 0, 0} Nat Nat Nat (instHPow.{0, 0} Nat Nat instPowNat) (OfNat.ofNat.{0} Nat 2 (instOfNatNat 2)) (HSub.hSub.{0, 0, 0} Nat Nat Nat (instHSub.{0} Nat instSubNat) (Fintype.card.{u1} α _inst_1) (Finset.card.{u2} ι s)))))
+Case conversion may be inaccurate. Consider using '#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersectingₓ'. -/
/-- **Kleitman's theorem**. An intersecting family on `n` elements contains at most `2ⁿ⁻¹` sets, and
each further intersecting family takes at most half of the sets that are in no previous family. -/
-theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
+theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
(hf : ∀ i ∈ s, (f i : Set (Finset α)).Intersecting) :
- (s.bunionᵢ f).card ≤ 2 ^ card α - 2 ^ (card α - s.card) :=
+ (s.biUnion f).card ≤ 2 ^ card α - 2 ^ (card α - s.card) :=
by
obtain hs | hs := le_total (card α) s.card
· rw [tsub_eq_zero_of_le hs, pow_zero]
@@ -90,7 +90,7 @@ theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Fin
(mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans
_
· rw [coe_bUnion]
- exact isUpperSet_unionᵢ₂ fun i hi => hf₂ _ <| subset_cons _ hi
+ exact isUpperSet_iUnion₂ fun i hi => hf₂ _ <| subset_cons _ hi
· rw [coe_compl]
exact (hf₂ _ <| mem_cons_self _ _).compl
rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
@@ -106,5 +106,5 @@ theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Fin
rw [mul_tsub, two_mul, ← pow_succ, ←
add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
-#align finset.card_bUnion_le_of_intersecting Finset.card_bunionᵢ_le_of_intersecting
+#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
mathlib commit https://github.com/leanprover-community/mathlib/commit/bd9851ca476957ea4549eb19b40e7b5ade9428cc
We change the following field in the definition of an additive commutative monoid:
nsmul_succ : ∀ (n : ℕ) (x : G),
- AddMonoid.nsmul (n + 1) x = x + AddMonoid.nsmul n x
+ AddMonoid.nsmul (n + 1) x = AddMonoid.nsmul n x + x
where the latter is more natural
We adjust the definitions of ^ in monoids, groups, etc.
Originally there was a warning comment about why this natural order was preferred
use
x * npowRec n xand notnpowRec n x * xin the definition to make sure that definitional unfolding ofnpowRecis blocked, to avoid deep recursion issues.
but it seems to no longer apply.
Remarks on the PR :
pow_succ and pow_succ' have switched their meanings.Ideal.IsPrime.mul_mem_pow which is defined in [Mathlib/RingTheory/DedekindDomain/Ideal.lean]. Changing the order of operation forced me to add the symmetric lemma Ideal.IsPrime.mem_pow_mul.@@ -64,7 +64,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
rw [union_sdiff_left, sdiff_eq_inter_compl]
refine' le_of_mul_le_mul_left _ (pow_pos (zero_lt_two' ℕ) <| Fintype.card α + 1)
- rw [pow_succ', mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
+ rw [pow_succ, mul_add, mul_assoc, mul_comm _ 2, mul_assoc]
refine' (add_le_add
((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
(hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
@@ -80,7 +80,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
refine' (add_le_add_left
(ih _ (fun i hi ↦ (hf₁ _ <| subset_cons _ hi).2.2)
((card_le_card <| subset_cons _).trans hs)) _).trans _
- rw [mul_tsub, two_mul, ← pow_succ,
+ rw [mul_tsub, two_mul, ← pow_succ',
← add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
This is a very large PR, but it has been reviewed piecemeal already in PRs to the bump/v4.7.0 branch as we update to intermediate nightlies.
Co-authored-by: Scott Morrison <scott.morrison@gmail.com> Co-authored-by: Kyle Miller <kmill31415@gmail.com> Co-authored-by: damiano <adomani@gmail.com>
@@ -52,7 +52,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
have hf₁ : ∀ j, j ∈ cons i s hi → f j ⊆ f' j ∧ 2 * (f' j).card =
2 ^ Fintype.card α ∧ (f' j : Set (Finset α)).Intersecting := by
rintro j hj
- simp_rw [dif_pos hj, ← Fintype.card_finset]
+ simp_rw [f', dif_pos hj, ← Fintype.card_finset]
exact Classical.choose_spec (hf j hj).exists_card_eq
have hf₂ : ∀ j, j ∈ cons i s hi → IsUpperSet (f' j : Set (Finset α)) := by
refine' fun j hj ↦ (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
Finset lemma names (#8894)
Change a few lemma names that have historically bothered me.
Finset.card_le_of_subset → Finset.card_le_cardMultiset.card_le_of_le → Multiset.card_le_cardMultiset.card_lt_of_lt → Multiset.card_lt_cardSet.ncard_le_of_subset → Set.ncard_le_ncardFinset.image_filter → Finset.filter_imageCompleteLattice.finset_sup_compact_of_compact → CompleteLattice.isCompactElement_finset_sup@@ -42,7 +42,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
infer_instance
obtain hs | hs := le_total (Fintype.card α) s.card
· rw [tsub_eq_zero_of_le hs, pow_zero]
- refine' (card_le_of_subset <| biUnion_subset.2 fun i hi a ha ↦
+ refine' (card_le_card <| biUnion_subset.2 fun i hi a ha ↦
mem_compl.2 <| not_mem_singleton.2 <| (hf _ hi).ne_bot ha).trans_eq _
rw [card_compl, Fintype.card_finset, card_singleton]
induction' s using Finset.cons_induction with i s hi ih generalizing f
@@ -58,7 +58,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
refine' fun j hj ↦ (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
rw [Fintype.card_finset]
exact (hf₁ _ hj).2.1
- refine' (card_le_of_subset <| biUnion_mono fun j hj ↦ (hf₁ _ hj).1).trans _
+ refine' (card_le_card <| biUnion_mono fun j hj ↦ (hf₁ _ hj).1).trans _
nth_rw 1 [cons_eq_insert i]
rw [biUnion_insert]
refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
@@ -79,7 +79,7 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
refine' mul_le_mul_left' _ _
refine' (add_le_add_left
(ih _ (fun i hi ↦ (hf₁ _ <| subset_cons _ hi).2.2)
- ((card_le_of_subset <| subset_cons _).trans hs)) _).trans _
+ ((card_le_card <| subset_cons _).trans hs)) _).trans _
rw [mul_tsub, two_mul, ← pow_succ,
← add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
The names for lemmas about monotonicity of (a ^ ·) and (· ^ n) were a mess. This PR tidies up everything related by following the naming convention for (a * ·) and (· * b). Namely, (a ^ ·) is pow_right and (· ^ n) is pow_left in lemma names. All lemma renames follow the corresponding multiplication lemma names closely.
Algebra.GroupPower.Orderpow_mono → pow_right_monopow_le_pow → pow_le_pow_rightpow_le_pow_of_le_left → pow_le_pow_leftpow_lt_pow_of_lt_left → pow_lt_pow_leftstrictMonoOn_pow → pow_left_strictMonoOnpow_strictMono_right → pow_right_strictMonopow_lt_pow → pow_lt_pow_rightpow_lt_pow_iff → pow_lt_pow_iff_rightpow_le_pow_iff → pow_le_pow_iff_rightself_lt_pow → lt_self_powstrictAnti_pow → pow_right_strictAntipow_lt_pow_iff_of_lt_one → pow_lt_pow_iff_right_of_lt_onepow_lt_pow_of_lt_one → pow_lt_pow_right_of_lt_onelt_of_pow_lt_pow → lt_of_pow_lt_pow_leftle_of_pow_le_pow → le_of_pow_le_pow_leftpow_lt_pow₀ → pow_lt_pow_right₀Algebra.GroupPower.CovariantClasspow_le_pow_of_le_left' → pow_le_pow_left'nsmul_le_nsmul_of_le_right → nsmul_le_nsmul_rightpow_lt_pow' → pow_lt_pow_right'nsmul_lt_nsmul → nsmul_lt_nsmul_leftpow_strictMono_left → pow_right_strictMono'nsmul_strictMono_right → nsmul_left_strictMonoStrictMono.pow_right' → StrictMono.pow_constStrictMono.nsmul_left → StrictMono.const_nsmulpow_strictMono_right' → pow_left_strictMononsmul_strictMono_left → nsmul_right_strictMonoMonotone.pow_right → Monotone.pow_constMonotone.nsmul_left → Monotone.const_nsmullt_of_pow_lt_pow' → lt_of_pow_lt_pow_left'lt_of_nsmul_lt_nsmul → lt_of_nsmul_lt_nsmul_rightpow_le_pow' → pow_le_pow_right'nsmul_le_nsmul → nsmul_le_nsmul_leftpow_le_pow_of_le_one' → pow_le_pow_right_of_le_one'nsmul_le_nsmul_of_nonpos → nsmul_le_nsmul_left_of_nonposle_of_pow_le_pow' → le_of_pow_le_pow_left'le_of_nsmul_le_nsmul' → le_of_nsmul_le_nsmul_right'pow_le_pow_iff' → pow_le_pow_iff_right'nsmul_le_nsmul_iff → nsmul_le_nsmul_iff_leftpow_lt_pow_iff' → pow_lt_pow_iff_right'nsmul_lt_nsmul_iff → nsmul_lt_nsmul_iff_leftData.Nat.PowNat.pow_lt_pow_of_lt_left → Nat.pow_lt_pow_leftNat.pow_le_iff_le_left → Nat.pow_le_pow_iff_leftNat.pow_lt_iff_lt_left → Nat.pow_lt_pow_iff_leftpow_le_pow_iff_leftpow_lt_pow_iff_leftpow_right_injectivepow_right_injNat.pow_le_pow_left to have the correct name since Nat.pow_le_pow_of_le_left is in Std.Nat.pow_le_pow_right to have the correct name since Nat.pow_le_pow_of_le_right is in Std.self_le_pow was a duplicate of le_self_pow.Nat.pow_lt_pow_of_lt_right is defeq to pow_lt_pow_right.Nat.pow_right_strictMono is defeq to pow_right_strictMono.Nat.pow_le_iff_le_right is defeq to pow_le_pow_iff_right.Nat.pow_lt_iff_lt_right is defeq to pow_lt_pow_iff_right.0 < n or 1 ≤ n to n ≠ 0.Nat lemmas have been protected.@@ -81,6 +81,6 @@ theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finse
(ih _ (fun i hi ↦ (hf₁ _ <| subset_cons _ hi).2.2)
((card_le_of_subset <| subset_cons _).trans hs)) _).trans _
rw [mul_tsub, two_mul, ← pow_succ,
- ← add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
+ ← add_tsub_assoc_of_le (pow_le_pow_right' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
Type _ and Sort _ (#6499)
We remove all possible occurences of Type _ and Sort _ in favor of Type* and Sort*.
This has nice performance benefits.
@@ -30,7 +30,7 @@ open Finset
open Fintype (card)
-variable {ι α : Type _} [Fintype α] [DecidableEq α] [Nonempty α]
+variable {ι α : Type*} [Fintype α] [DecidableEq α] [Nonempty α]
/-- **Kleitman's theorem**. An intersecting family on `n` elements contains at most `2ⁿ⁻¹` sets, and
each further intersecting family takes at most half of the sets that are in no previous family. -/
@@ -2,15 +2,12 @@
Copyright (c) 2022 Yaël Dillies. All rights reserved.
Released under Apache 2.0 license as described in the file LICENSE.
Authors: Yaël Dillies
-
-! This file was ported from Lean 3 source module combinatorics.set_family.kleitman
-! leanprover-community/mathlib commit 4c19a16e4b705bf135cf9a80ac18fcc99c438514
-! Please do not edit these lines, except to modify the commit id
-! if you have ported upstream changes.
-/
import Mathlib.Combinatorics.SetFamily.HarrisKleitman
import Mathlib.Combinatorics.SetFamily.Intersecting
+#align_import combinatorics.set_family.kleitman from "leanprover-community/mathlib"@"4c19a16e4b705bf135cf9a80ac18fcc99c438514"
+
/-!
# Kleitman's bound on the size of intersecting families
sSup/iSup (#3938)
As discussed on Zulip
supₛ → sSupinfₛ → sInfsupᵢ → iSupinfᵢ → iInfbsupₛ → bsSupbinfₛ → bsInfbsupᵢ → biSupbinfᵢ → biInfcsupₛ → csSupcinfₛ → csInfcsupᵢ → ciSupcinfᵢ → ciInfunionₛ → sUnioninterₛ → sInterunionᵢ → iUnioninterᵢ → iInterbunionₛ → bsUnionbinterₛ → bsInterbunionᵢ → biUnionbinterᵢ → biInterCo-authored-by: Parcly Taxel <reddeloostw@gmail.com>
@@ -21,7 +21,7 @@ Kleitman's bound stipulates that `k` intersecting families cover at most `2ⁿ -
## Main declarations
-* `Finset.card_bunionᵢ_le_of_intersecting`: Kleitman's theorem.
+* `Finset.card_biUnion_le_of_intersecting`: Kleitman's theorem.
## References
@@ -37,15 +37,15 @@ variable {ι α : Type _} [Fintype α] [DecidableEq α] [Nonempty α]
/-- **Kleitman's theorem**. An intersecting family on `n` elements contains at most `2ⁿ⁻¹` sets, and
each further intersecting family takes at most half of the sets that are in no previous family. -/
-theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
+theorem Finset.card_biUnion_le_of_intersecting (s : Finset ι) (f : ι → Finset (Finset α))
(hf : ∀ i ∈ s, (f i : Set (Finset α)).Intersecting) :
- (s.bunionᵢ f).card ≤ 2 ^ Fintype.card α - 2 ^ (Fintype.card α - s.card) := by
+ (s.biUnion f).card ≤ 2 ^ Fintype.card α - 2 ^ (Fintype.card α - s.card) := by
have : DecidableEq ι := by
classical
infer_instance
obtain hs | hs := le_total (Fintype.card α) s.card
· rw [tsub_eq_zero_of_le hs, pow_zero]
- refine' (card_le_of_subset <| bunionᵢ_subset.2 fun i hi a ha ↦
+ refine' (card_le_of_subset <| biUnion_subset.2 fun i hi a ha ↦
mem_compl.2 <| not_mem_singleton.2 <| (hf _ hi).ne_bot ha).trans_eq _
rw [card_compl, Fintype.card_finset, card_singleton]
induction' s using Finset.cons_induction with i s hi ih generalizing f
@@ -61,9 +61,9 @@ theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Fin
refine' fun j hj ↦ (hf₁ _ hj).2.2.isUpperSet' ((hf₁ _ hj).2.2.is_max_iff_card_eq.2 _)
rw [Fintype.card_finset]
exact (hf₁ _ hj).2.1
- refine' (card_le_of_subset <| bunionᵢ_mono fun j hj ↦ (hf₁ _ hj).1).trans _
+ refine' (card_le_of_subset <| biUnion_mono fun j hj ↦ (hf₁ _ hj).1).trans _
nth_rw 1 [cons_eq_insert i]
- rw [bunionᵢ_insert]
+ rw [biUnion_insert]
refine' (card_mono <| @le_sup_sdiff _ _ _ <| f' i).trans ((card_union_le _ _).trans _)
rw [union_sdiff_left, sdiff_eq_inter_compl]
refine' le_of_mul_le_mul_left _ (pow_pos (zero_lt_two' ℕ) <| Fintype.card α + 1)
@@ -72,8 +72,8 @@ theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Fin
((mul_le_mul_left <| pow_pos (zero_lt_two' ℕ) _).2
(hf₁ _ <| mem_cons_self _ _).2.2.card_le) <|
(mul_le_mul_left <| zero_lt_two' ℕ).2 <| IsUpperSet.card_inter_le_finset _ _).trans _
- · rw [coe_bunionᵢ]
- exact isUpperSet_unionᵢ₂ fun i hi ↦ hf₂ _ <| subset_cons _ hi
+ · rw [coe_biUnion]
+ exact isUpperSet_iUnion₂ fun i hi ↦ hf₂ _ <| subset_cons _ hi
· rw [coe_compl]
exact (hf₂ _ <| mem_cons_self _ _).compl
rw [mul_tsub, card_compl, Fintype.card_finset, mul_left_comm, mul_tsub,
@@ -86,4 +86,4 @@ theorem Finset.card_bunionᵢ_le_of_intersecting (s : Finset ι) (f : ι → Fin
rw [mul_tsub, two_mul, ← pow_succ,
← add_tsub_assoc_of_le (pow_le_pow' (one_le_two : (1 : ℕ) ≤ 2) tsub_le_self),
tsub_add_eq_add_tsub hs, card_cons, add_tsub_add_eq_tsub_right]
-#align finset.card_bUnion_le_of_intersecting Finset.card_bunionᵢ_le_of_intersecting
+#align finset.card_bUnion_le_of_intersecting Finset.card_biUnion_le_of_intersecting
The unported dependencies are