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mk_union_of_disjoint {α : Type u} {S T : set α} (H : disjoint S T) : #(S ∪ T : set α) = #S + #T
quot.sound ⟨equiv.set.union H.le_bot⟩
theorem
cardinal.mk_union_of_disjoint
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "disjoint" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_insert {α : Type u} {s : set α} {a : α} (h : a ∉ s) : #(insert a s : set α) = #s + 1
by { rw [← union_singleton, mk_union_of_disjoint, mk_singleton], simpa }
theorem
cardinal.mk_insert
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_sum_compl {α} (s : set α) : #s + #(sᶜ : set α) = #α
mk_congr (equiv.set.sum_compl s)
lemma
cardinal.mk_sum_compl
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.set.sum_compl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_le_mk_of_subset {α} {s t : set α} (h : s ⊆ t) : #s ≤ #t
⟨set.embedding_of_subset s t h⟩
lemma
cardinal.mk_le_mk_of_subset
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_subtype_mono {p q : α → Prop} (h : ∀ x, p x → q x) : #{x // p x} ≤ #{x // q x}
⟨embedding_of_subset _ _ h⟩
lemma
cardinal.mk_subtype_mono
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mk_diff_add_mk (S T : set α) : #S ≤ #(S \ T : set α) + #T
(mk_le_mk_of_subset $ subset_diff_union _ _).trans $ mk_union_le _ _
lemma
cardinal.le_mk_diff_add_mk
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_diff_add_mk {S T : set α} (h : T ⊆ S) : #(S \ T : set α) + #T = #S
(mk_union_of_disjoint $ by exact disjoint_sdiff_self_left).symm.trans $ by rw diff_union_of_subset h
lemma
cardinal.mk_diff_add_mk
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "disjoint_sdiff_self_left" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_union_le_aleph_0 {α} {P Q : set α} : #((P ∪ Q : set α)) ≤ ℵ₀ ↔ #P ≤ ℵ₀ ∧ #Q ≤ ℵ₀
by simp
lemma
cardinal.mk_union_le_aleph_0
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_image_eq_lift {α : Type u} {β : Type v} (f : α → β) (s : set α) (h : injective f) : lift.{u} (#(f '' s)) = lift.{v} (#s)
lift_mk_eq.{v u 0}.mpr ⟨(equiv.set.image f s h).symm⟩
lemma
cardinal.mk_image_eq_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.set.image" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_image_eq_of_inj_on_lift {α : Type u} {β : Type v} (f : α → β) (s : set α) (h : inj_on f s) : lift.{u} (#(f '' s)) = lift.{v} (#s)
lift_mk_eq.{v u 0}.mpr ⟨(equiv.set.image_of_inj_on f s h).symm⟩
lemma
cardinal.mk_image_eq_of_inj_on_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.set.image_of_inj_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_image_eq_of_inj_on {α β : Type u} (f : α → β) (s : set α) (h : inj_on f s) : #(f '' s) = #s
mk_congr ((equiv.set.image_of_inj_on f s h).symm)
lemma
cardinal.mk_image_eq_of_inj_on
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.set.image_of_inj_on" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_subtype_of_equiv {α β : Type u} (p : β → Prop) (e : α ≃ β) : #{a : α // p (e a)} = #{b : β // p b}
mk_congr (equiv.subtype_equiv_of_subtype e)
lemma
cardinal.mk_subtype_of_equiv
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.subtype_equiv_of_subtype" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_sep (s : set α) (t : α → Prop) : #({ x ∈ s | t x } : set α) = #{ x : s | t x.1 }
mk_congr (equiv.set.sep s t)
lemma
cardinal.mk_sep
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "equiv.set.sep" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_injective_lift {α : Type u} {β : Type v} (f : α → β) (s : set β) (h : injective f) : lift.{v} (#(f ⁻¹' s)) ≤ lift.{u} (#s)
begin rw lift_mk_le.{u v 0}, use subtype.coind (λ x, f x.1) (λ x, x.2), apply subtype.coind_injective, exact h.comp subtype.val_injective end
lemma
cardinal.mk_preimage_of_injective_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "subtype.coind", "subtype.coind_injective", "subtype.val_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_subset_range_lift {α : Type u} {β : Type v} (f : α → β) (s : set β) (h : s ⊆ range f) : lift.{u} (#s) ≤ lift.{v} (#(f ⁻¹' s))
begin rw lift_mk_le.{v u 0}, refine ⟨⟨_, _⟩⟩, { rintro ⟨y, hy⟩, rcases classical.subtype_of_exists (h hy) with ⟨x, rfl⟩, exact ⟨x, hy⟩ }, rintro ⟨y, hy⟩ ⟨y', hy'⟩, dsimp, rcases classical.subtype_of_exists (h hy) with ⟨x, rfl⟩, rcases classical.subtype_of_exists (h hy') with ⟨x', rfl⟩, simp, intro hxx', r...
lemma
cardinal.mk_preimage_of_subset_range_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "classical.subtype_of_exists" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_injective_of_subset_range_lift {β : Type v} (f : α → β) (s : set β) (h : injective f) (h2 : s ⊆ range f) : lift.{v} (#(f ⁻¹' s)) = lift.{u} (#s)
le_antisymm (mk_preimage_of_injective_lift f s h) (mk_preimage_of_subset_range_lift f s h2)
lemma
cardinal.mk_preimage_of_injective_of_subset_range_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_injective (f : α → β) (s : set β) (h : injective f) : #(f ⁻¹' s) ≤ #s
by { convert mk_preimage_of_injective_lift.{u u} f s h using 1; rw [lift_id] }
lemma
cardinal.mk_preimage_of_injective
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_subset_range (f : α → β) (s : set β) (h : s ⊆ range f) : #s ≤ #(f ⁻¹' s)
by { convert mk_preimage_of_subset_range_lift.{u u} f s h using 1; rw [lift_id] }
lemma
cardinal.mk_preimage_of_subset_range
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_preimage_of_injective_of_subset_range (f : α → β) (s : set β) (h : injective f) (h2 : s ⊆ range f) : #(f ⁻¹' s) = #s
by { convert mk_preimage_of_injective_of_subset_range_lift.{u u} f s h h2 using 1; rw [lift_id] }
lemma
cardinal.mk_preimage_of_injective_of_subset_range
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_subset_ge_of_subset_image_lift {α : Type u} {β : Type v} (f : α → β) {s : set α} {t : set β} (h : t ⊆ f '' s) : lift.{u} (#t) ≤ lift.{v} (#({ x ∈ s | f x ∈ t } : set α))
by { rw [image_eq_range] at h, convert mk_preimage_of_subset_range_lift _ _ h using 1, rw [mk_sep], refl }
lemma
cardinal.mk_subset_ge_of_subset_image_lift
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_subset_ge_of_subset_image (f : α → β) {s : set α} {t : set β} (h : t ⊆ f '' s) : #t ≤ #({ x ∈ s | f x ∈ t } : set α)
by { rw [image_eq_range] at h, convert mk_preimage_of_subset_range _ _ h using 1, rw [mk_sep], refl }
lemma
cardinal.mk_subset_ge_of_subset_image
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mk_iff_exists_subset {c : cardinal} {α : Type u} {s : set α} : c ≤ #s ↔ ∃ p : set α, p ⊆ s ∧ #p = c
begin rw [le_mk_iff_exists_set, ←subtype.exists_set_subtype], apply exists_congr, intro t, rw [mk_image_eq], apply subtype.val_injective end
theorem
cardinal.le_mk_iff_exists_subset
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal", "subtype.val_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
two_le_iff : (2 : cardinal) ≤ #α ↔ ∃x y : α, x ≠ y
by rw [← nat.cast_two, nat_succ, succ_le_iff, nat.cast_one, one_lt_iff_nontrivial, nontrivial_iff]
lemma
cardinal.two_le_iff
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal", "nat.cast_one", "nat.cast_two", "nontrivial_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
two_le_iff' (x : α) : (2 : cardinal) ≤ #α ↔ ∃y : α, y ≠ x
by rw [two_le_iff, ← nontrivial_iff, nontrivial_iff_exists_ne x]
lemma
cardinal.two_le_iff'
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal", "nontrivial_iff", "nontrivial_iff_exists_ne" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_eq_two_iff : #α = 2 ↔ ∃ x y : α, x ≠ y ∧ ({x, y} : set α) = univ
begin simp only [← @nat.cast_two cardinal, mk_eq_nat_iff_finset, finset.card_eq_two], split, { rintro ⟨t, ht, x, y, hne, rfl⟩, exact ⟨x, y, hne, by simpa using ht⟩ }, { rintro ⟨x, y, hne, h⟩, exact ⟨{x, y}, by simpa using h, x, y, hne, rfl⟩ } end
lemma
cardinal.mk_eq_two_iff
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal", "finset.card_eq_two", "nat.cast_two" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mk_eq_two_iff' (x : α) : #α = 2 ↔ ∃! y, y ≠ x
begin rw [mk_eq_two_iff], split, { rintro ⟨a, b, hne, h⟩, simp only [eq_univ_iff_forall, mem_insert_iff, mem_singleton_iff] at h, rcases h x with rfl|rfl, exacts [⟨b, hne.symm, λ z, (h z).resolve_left⟩, ⟨a, hne, λ z, (h z).resolve_right⟩] }, { rintro ⟨y, hne, hy⟩, exact ⟨x, y, hne.symm, eq_univ_of...
lemma
cardinal.mk_eq_two_iff'
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_not_mem_of_length_lt {α : Type*} (l : list α) (h : ↑l.length < # α) : ∃ (z : α), z ∉ l
begin contrapose! h, calc # α = # (set.univ : set α) : mk_univ.symm ... ≤ # l.to_finset : mk_le_mk_of_subset (λ x _, list.mem_to_finset.mpr (h x)) ... = l.to_finset.card : cardinal.mk_coe_finset ... ≤ l.length : cardinal.nat_cast_le.mpr (list.to_finset_card_le l), end
lemma
cardinal.exists_not_mem_of_length_lt
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal.mk_coe_finset", "list.to_finset_card_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
three_le {α : Type*} (h : 3 ≤ # α) (x : α) (y : α) : ∃ (z : α), z ≠ x ∧ z ≠ y
begin have : ↑(3 : ℕ) ≤ # α, simpa using h, have : ↑(2 : ℕ) < # α, rwa [← succ_le_iff, ← cardinal.nat_succ], have := exists_not_mem_of_length_lt [x, y] this, simpa [not_or_distrib] using this, end
lemma
cardinal.three_le
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal.nat_succ", "not_or_distrib" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt (a b : cardinal.{u}) : cardinal.{u}
⨆ c : Iio b, a ^ c
def
cardinal.powerlt
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
The function `a ^< b`, defined as the supremum of `a ^ c` for `c < b`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_powerlt {b c : cardinal.{u}} (a) (h : c < b) : a ^ c ≤ a ^< b
begin apply @le_csupr _ _ _ (λ y : Iio b, a ^ y) _ ⟨c, h⟩, rw ←image_eq_range, exact bdd_above_image.{u u} _ bdd_above_Iio end
lemma
cardinal.le_powerlt
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "bdd_above_Iio", "le_csupr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_le {a b c : cardinal.{u}} : a ^< b ≤ c ↔ ∀ x < b, a ^ x ≤ c
begin rw [powerlt, csupr_le_iff'], { simp }, { rw ←image_eq_range, exact bdd_above_image.{u u} _ bdd_above_Iio } end
lemma
cardinal.powerlt_le
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "bdd_above_Iio", "csupr_le_iff'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_le_powerlt_left {a b c : cardinal} (h : b ≤ c) : a ^< b ≤ a ^< c
powerlt_le.2 $ λ x hx, le_powerlt a $ hx.trans_le h
lemma
cardinal.powerlt_le_powerlt_left
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_mono_left (a) : monotone (λ c, a ^< c)
λ b c, powerlt_le_powerlt_left
lemma
cardinal.powerlt_mono_left
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_succ {a b : cardinal} (h : a ≠ 0) : a ^< (succ b) = a ^ b
(powerlt_le.2 $ λ c h', power_le_power_left h $ le_of_lt_succ h').antisymm $ le_powerlt a (lt_succ b)
lemma
cardinal.powerlt_succ
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_min {a b c : cardinal} : a ^< min b c = min (a ^< b) (a ^< c)
(powerlt_mono_left a).map_min
lemma
cardinal.powerlt_min
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_max {a b c : cardinal} : a ^< max b c = max (a ^< b) (a ^< c)
(powerlt_mono_left a).map_max
lemma
cardinal.powerlt_max
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_powerlt {a : cardinal} (h : a ≠ 0) : 0 ^< a = 1
begin apply (powerlt_le.2 (λ c hc, zero_power_le _)).antisymm, rw ←power_zero, exact le_powerlt 0 (pos_iff_ne_zero.2 h) end
lemma
cardinal.zero_powerlt
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
powerlt_zero {a : cardinal} : a ^< 0 = 0
begin convert cardinal.supr_of_empty _, exact subtype.is_empty_of_false (λ x, (cardinal.zero_le _).not_lt), end
lemma
cardinal.powerlt_zero
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[ "cardinal", "cardinal.supr_of_empty", "cardinal.zero_le", "subtype.is_empty_of_false" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
positivity_cardinal_pow : expr → tactic strictness
| `(@has_pow.pow _ _ %%inst %%a %%b) := do strictness_a ← core a, match strictness_a with | positive p := positive <$> mk_app ``power_pos [b, p] | _ := failed -- We already know that `0 ≤ x` for all `x : cardinal` end | _ := failed
def
tactic.positivity_cardinal_pow
set_theory.cardinal
src/set_theory/cardinal/basic.lean
[ "data.fintype.big_operators", "data.finsupp.defs", "data.nat.part_enat", "data.set.countable", "logic.small.basic", "order.conditionally_complete_lattice.basic", "order.succ_pred.limit", "set_theory.cardinal.schroeder_bernstein", "tactic.positivity" ]
[]
Extension for the `positivity` tactic: The cardinal power of a positive cardinal is positive.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof (r : α → α → Prop) : cardinal
Inf {c | ∃ S : set α, (∀ a, ∃ b ∈ S, r a b) ∧ #S = c}
def
order.cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal" ]
Cofinality of a reflexive order `≼`. This is the smallest cardinality of a subset `S : set α` such that `∀ a, ∃ b ∈ S, a ≼ b`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_nonempty (r : α → α → Prop) [is_refl α r] : {c | ∃ S : set α, (∀ a, ∃ b ∈ S, r a b) ∧ #S = c}.nonempty
⟨_, set.univ, λ a, ⟨a, ⟨⟩, refl _⟩, rfl⟩
theorem
order.cof_nonempty
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
The set in the definition of `order.cof` is nonempty.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_le (r : α → α → Prop) {S : set α} (h : ∀ a, ∃ b ∈ S, r a b) : cof r ≤ #S
cInf_le' ⟨S, h, rfl⟩
lemma
order.cof_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cInf_le'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_cof {r : α → α → Prop} [is_refl α r] (c : cardinal) : c ≤ cof r ↔ ∀ {S : set α}, (∀ a, ∃ b ∈ S, r a b) → c ≤ #S
begin rw [cof, le_cInf_iff'' (cof_nonempty r)], use λ H S h, H _ ⟨S, h, rfl⟩, rintro H d ⟨S, h, rfl⟩, exact H h end
lemma
order.le_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "le_cInf_iff''" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso.cof_le_lift {α : Type u} {β : Type v} {r : α → α → Prop} {s} [is_refl β s] (f : r ≃r s) : cardinal.lift.{max u v} (order.cof r) ≤ cardinal.lift.{max u v} (order.cof s)
begin rw [order.cof, order.cof, lift_Inf, lift_Inf, le_cInf_iff'' (nonempty_image_iff.2 (order.cof_nonempty s))], rintros - ⟨-, ⟨u, H, rfl⟩, rfl⟩, apply cInf_le', refine ⟨_, ⟨f.symm '' u, λ a, _, rfl⟩, lift_mk_eq.{u v (max u v)}.2 ⟨((f.symm).to_equiv.image u).symm⟩⟩, rcases H (f a) with ⟨b, hb, hb'⟩, ...
theorem
rel_iso.cof_le_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cInf_le'", "le_cInf_iff''", "order.cof", "order.cof_nonempty", "rel_iso.apply_symm_apply" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso.cof_eq_lift {α : Type u} {β : Type v} {r s} [is_refl α r] [is_refl β s] (f : r ≃r s) : cardinal.lift.{max u v} (order.cof r) = cardinal.lift.{max u v} (order.cof s)
(rel_iso.cof_le_lift f).antisymm (rel_iso.cof_le_lift f.symm)
theorem
rel_iso.cof_eq_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "order.cof", "rel_iso.cof_le_lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso.cof_le {α β : Type u} {r : α → α → Prop} {s} [is_refl β s] (f : r ≃r s) : order.cof r ≤ order.cof s
lift_le.1 (rel_iso.cof_le_lift f)
theorem
rel_iso.cof_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "order.cof", "rel_iso.cof_le_lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rel_iso.cof_eq {α β : Type u} {r s} [is_refl α r] [is_refl β s] (f : r ≃r s) : order.cof r = order.cof s
lift_inj.1 (rel_iso.cof_eq_lift f)
theorem
rel_iso.cof_eq
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "order.cof", "rel_iso.cof_eq_lift" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strict_order.cof (r : α → α → Prop) : cardinal
order.cof (swap r)ᶜ
def
strict_order.cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "order.cof" ]
Cofinality of a strict order `≺`. This is the smallest cardinality of a set `S : set α` such that `∀ a, ∃ b ∈ S, ¬ b ≺ a`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strict_order.cof_nonempty (r : α → α → Prop) [is_irrefl α r] : {c | ∃ S : set α, unbounded r S ∧ #S = c}.nonempty
@order.cof_nonempty α _ (is_refl.swap rᶜ)
theorem
strict_order.cof_nonempty
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_refl.swap", "order.cof_nonempty" ]
The set in the definition of `order.strict_order.cof` is nonempty.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof (o : ordinal.{u}) : cardinal.{u}
o.lift_on (λ a, strict_order.cof a.r) begin rintros ⟨α, r, wo₁⟩ ⟨β, s, wo₂⟩ ⟨⟨f, hf⟩⟩, haveI := wo₁, haveI := wo₂, apply @rel_iso.cof_eq _ _ _ _ _ _ , { split, exact λ a b, not_iff_not.2 hf }, { exact ⟨(is_well_order.is_irrefl r).1⟩ }, { exact ⟨(is_well_order.is_irrefl s).1⟩ } end
def
ordinal.cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_well_order.is_irrefl", "rel_iso.cof_eq", "strict_order.cof" ]
Cofinality of an ordinal. This is the smallest cardinal of a subset `S` of the ordinal which is unbounded, in the sense `∀ a, ∃ b ∈ S, a ≤ b`. It is defined for all ordinals, but `cof 0 = 0` and `cof (succ o) = 1`, so it is only really interesting on limit ordinals (when it is an infinite cardinal).
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_type (r : α → α → Prop) [is_well_order α r] : (type r).cof = strict_order.cof r
rfl
lemma
ordinal.cof_type
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_well_order", "strict_order.cof" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_cof_type [is_well_order α r] {c} : c ≤ cof (type r) ↔ ∀ S, unbounded r S → c ≤ #S
(le_cInf_iff'' (strict_order.cof_nonempty r)).trans ⟨λ H S h, H _ ⟨S, h, rfl⟩, by { rintros H d ⟨S, h, rfl⟩, exact H _ h }⟩
theorem
ordinal.le_cof_type
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_well_order", "le_cInf_iff''", "strict_order.cof_nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_type_le [is_well_order α r] {S : set α} (h : unbounded r S) : cof (type r) ≤ #S
le_cof_type.1 le_rfl S h
theorem
ordinal.cof_type_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_well_order", "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_cof_type [is_well_order α r] {S : set α} : #S < cof (type r) → bounded r S
by simpa using not_imp_not.2 cof_type_le
theorem
ordinal.lt_cof_type
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_eq (r : α → α → Prop) [is_well_order α r] : ∃ S, unbounded r S ∧ #S = cof (type r)
Inf_mem (strict_order.cof_nonempty r)
theorem
ordinal.cof_eq
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "Inf_mem", "is_well_order", "strict_order.cof_nonempty" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ord_cof_eq (r : α → α → Prop) [is_well_order α r] : ∃ S, unbounded r S ∧ type (subrel r S) = (cof (type r)).ord
let ⟨S, hS, e⟩ := cof_eq r, ⟨s, _, e'⟩ := cardinal.ord_eq S, T : set α := {a | ∃ aS : a ∈ S, ∀ b : S, s b ⟨_, aS⟩ → r b a} in begin resetI, suffices, { refine ⟨T, this, le_antisymm _ (cardinal.ord_le.2 $ cof_type_le this)⟩, rw [← e, e'], refine (rel_embedding.of_monotone (λ a : T, (⟨a, let ⟨aS, _⟩...
theorem
ordinal.ord_cof_eq
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.ord_eq", "is_order_connected.neg_trans", "is_well_order", "rel_embedding.of_monotone", "subrel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
card_mem_cof {o} : ∃ {ι} (f : ι → ordinal), lsub.{u u} f = o ∧ #ι = o.card
⟨_, _, lsub_typein o, mk_ordinal_out o⟩
theorem
ordinal.card_mem_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_lsub_def_nonempty (o) : {a : cardinal | ∃ {ι} (f : ι → ordinal), lsub.{u u} f = o ∧ #ι = a}.nonempty
⟨_, card_mem_cof⟩
theorem
ordinal.cof_lsub_def_nonempty
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "ordinal" ]
The set in the `lsub` characterization of `cof` is nonempty.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_eq_Inf_lsub (o : ordinal.{u}) : cof o = Inf {a : cardinal | ∃ {ι : Type u} (f : ι → ordinal), lsub.{u u} f = o ∧ #ι = a}
begin refine le_antisymm (le_cInf (cof_lsub_def_nonempty o) _) (cInf_le' _), { rintros a ⟨ι, f, hf, rfl⟩, rw ←type_lt o, refine (cof_type_le (λ a, _)).trans (@mk_le_of_injective _ _ (λ s : (typein ((<) : o.out.α → o.out.α → Prop))⁻¹' (set.range f), classical.some s.prop) (λ s t hst, let H := con...
theorem
ordinal.cof_eq_Inf_lsub
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cInf_le'", "cardinal", "le_cInf", "le_of_forall_lt", "ordinal", "set.range", "subtype.coe_inj" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lift_cof (o) : (cof o).lift = cof o.lift
begin refine induction_on o _, introsI α r _, apply le_antisymm, { refine le_cof_type.2 (λ S H, _), have : (#(ulift.up ⁻¹' S)).lift ≤ #S, { rw [← cardinal.lift_umax, ← cardinal.lift_id' (#S)], exact mk_preimage_of_injective_lift ulift.up _ ulift.up_injective }, refine (cardinal.lift_le.2 $ cof...
theorem
ordinal.lift_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.lift_id'", "cardinal.lift_umax", "lift", "ulift.up_injective" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_le_card (o) : cof o ≤ card o
by { rw cof_eq_Inf_lsub, exact cInf_le' card_mem_cof }
theorem
ordinal.cof_le_card
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cInf_le'" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_ord_le (c : cardinal) : c.ord.cof ≤ c
by simpa using cof_le_card c.ord
theorem
ordinal.cof_ord_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ord_cof_le (o : ordinal.{u}) : o.cof.ord ≤ o
(ord_le_ord.2 (cof_le_card o)).trans (ord_card_le o)
theorem
ordinal.ord_cof_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_lsub_cof (o : ordinal) : ∃ {ι} (f : ι → ordinal), lsub.{u u} f = o ∧ #ι = cof o
by { rw cof_eq_Inf_lsub, exact Inf_mem (cof_lsub_def_nonempty o) }
theorem
ordinal.exists_lsub_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "Inf_mem", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_lsub_le {ι} (f : ι → ordinal) : cof (lsub.{u u} f) ≤ #ι
by { rw cof_eq_Inf_lsub, exact cInf_le' ⟨ι, f, rfl, rfl⟩ }
theorem
ordinal.cof_lsub_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cInf_le'", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_lsub_le_lift {ι} (f : ι → ordinal) : cof (lsub f) ≤ cardinal.lift.{v u} (#ι)
begin rw ←mk_ulift, convert cof_lsub_le (λ i : ulift ι, f i.down), exact lsub_eq_of_range_eq.{u (max u v) max u v} (set.ext (λ x, ⟨λ ⟨i, hi⟩, ⟨ulift.up i, hi⟩, λ ⟨i, hi⟩, ⟨_, hi⟩⟩)) end
theorem
ordinal.cof_lsub_le_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_cof_iff_lsub {o : ordinal} {a : cardinal} : a ≤ cof o ↔ ∀ {ι} (f : ι → ordinal), lsub.{u u} f = o → a ≤ #ι
begin rw cof_eq_Inf_lsub, exact (le_cInf_iff'' (cof_lsub_def_nonempty o)).trans ⟨λ H ι f hf, H _ ⟨ι, f, hf, rfl⟩, λ H b ⟨ι, f, hf, hb⟩, ( by { rw ←hb, exact H _ hf} )⟩ end
theorem
ordinal.le_cof_iff_lsub
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "le_cInf_iff''", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lsub_lt_ord_lift {ι} {f : ι → ordinal} {c : ordinal} (hι : cardinal.lift (#ι) < c.cof) (hf : ∀ i, f i < c) : lsub.{u v} f < c
lt_of_le_of_ne (lsub_le hf) (λ h, by { subst h, exact (cof_lsub_le_lift f).not_lt hι })
theorem
ordinal.lsub_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.lift", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lsub_lt_ord {ι} {f : ι → ordinal} {c : ordinal} (hι : #ι < c.cof) : (∀ i, f i < c) → lsub.{u u} f < c
lsub_lt_ord_lift (by rwa (#ι).lift_id)
theorem
ordinal.lsub_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_sup_le_lift {ι} {f : ι → ordinal} (H : ∀ i, f i < sup f) : cof (sup f) ≤ (#ι).lift
by { rw ←sup_eq_lsub_iff_lt_sup at H, rw H, exact cof_lsub_le_lift f }
theorem
ordinal.cof_sup_le_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "lift", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_sup_le {ι} {f : ι → ordinal} (H : ∀ i, f i < sup.{u u} f) : cof (sup.{u u} f) ≤ #ι
by { rw ←(#ι).lift_id, exact cof_sup_le_lift H }
theorem
ordinal.cof_sup_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_lt_ord_lift {ι} {f : ι → ordinal} {c : ordinal} (hι : cardinal.lift (#ι) < c.cof) (hf : ∀ i, f i < c) : sup.{u v} f < c
(sup_le_lsub.{u v} f).trans_lt (lsub_lt_ord_lift hι hf)
theorem
ordinal.sup_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.lift", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_lt_ord {ι} {f : ι → ordinal} {c : ordinal} (hι : #ι < c.cof) : (∀ i, f i < c) → sup.{u u} f < c
sup_lt_ord_lift (by rwa (#ι).lift_id)
theorem
ordinal.sup_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lt_lift {ι} {f : ι → cardinal} {c : cardinal} (hι : cardinal.lift (#ι) < c.ord.cof) (hf : ∀ i, f i < c) : supr f < c
begin rw [←ord_lt_ord, supr_ord (cardinal.bdd_above_range _)], refine sup_lt_ord_lift hι (λ i, _), rw ord_lt_ord, apply hf end
theorem
ordinal.supr_lt_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "cardinal.bdd_above_range", "cardinal.lift", "supr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
supr_lt {ι} {f : ι → cardinal} {c : cardinal} (hι : #ι < c.ord.cof) : (∀ i, f i < c) → supr f < c
supr_lt_lift (by rwa (#ι).lift_id)
theorem
ordinal.supr_lt
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "supr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_family_lt_ord_lift {ι} {f : ι → ordinal → ordinal} {c} (hc : ℵ₀ < cof c) (hc' : (#ι).lift < cof c) (hf : ∀ i (b < c), f i b < c) {a} (ha : a < c) : nfp_family.{u v} f a < c
begin refine sup_lt_ord_lift ((cardinal.lift_le.2 (mk_list_le_max ι)).trans_lt _) (λ l, _), { rw lift_max, apply max_lt _ hc', rwa cardinal.lift_aleph_0 }, { induction l with i l H, { exact ha }, { exact hf _ _ H } } end
theorem
ordinal.nfp_family_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.lift_aleph_0", "lift", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_family_lt_ord {ι} {f : ι → ordinal → ordinal} {c} (hc : ℵ₀ < cof c) (hc' : #ι < cof c) (hf : ∀ i (b < c), f i b < c) {a} : a < c → nfp_family.{u u} f a < c
nfp_family_lt_ord_lift hc (by rwa (#ι).lift_id) hf
theorem
ordinal.nfp_family_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_bfamily_lt_ord_lift {o : ordinal} {f : Π a < o, ordinal → ordinal} {c} (hc : ℵ₀ < cof c) (hc' : o.card.lift < cof c) (hf : ∀ i hi (b < c), f i hi b < c) {a} : a < c → nfp_bfamily.{u v} o f a < c
nfp_family_lt_ord_lift hc (by rwa mk_ordinal_out) (λ i, hf _ _)
theorem
ordinal.nfp_bfamily_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_bfamily_lt_ord {o : ordinal} {f : Π a < o, ordinal → ordinal} {c} (hc : ℵ₀ < cof c) (hc' : o.card < cof c) (hf : ∀ i hi (b < c), f i hi b < c) {a} : a < c → nfp_bfamily.{u u} o f a < c
nfp_bfamily_lt_ord_lift hc (by rwa o.card.lift_id) hf
theorem
ordinal.nfp_bfamily_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_lt_ord {f : ordinal → ordinal} {c} (hc : ℵ₀ < cof c) (hf : ∀ i < c, f i < c) {a} : a < c → nfp f a < c
nfp_family_lt_ord_lift hc (by simpa using cardinal.one_lt_aleph_0.trans hc) (λ _, hf)
theorem
ordinal.nfp_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
exists_blsub_cof (o : ordinal) : ∃ (f : Π a < (cof o).ord, ordinal), blsub.{u u} _ f = o
begin rcases exists_lsub_cof o with ⟨ι, f, hf, hι⟩, rcases cardinal.ord_eq ι with ⟨r, hr, hι'⟩, rw ←@blsub_eq_lsub' ι r hr at hf, rw [←hι, hι'], exact ⟨_, hf⟩ end
theorem
ordinal.exists_blsub_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.ord_eq", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_cof_iff_blsub {b : ordinal} {a : cardinal} : a ≤ cof b ↔ ∀ {o} (f : Π a < o, ordinal), blsub.{u u} o f = b → a ≤ o.card
le_cof_iff_lsub.trans ⟨λ H o f hf, by simpa using H _ hf, λ H ι f hf, begin rcases cardinal.ord_eq ι with ⟨r, hr, hι'⟩, rw ←@blsub_eq_lsub' ι r hr at hf, simpa using H _ hf end⟩
theorem
ordinal.le_cof_iff_blsub
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal", "cardinal.ord_eq", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_blsub_le_lift {o} (f : Π a < o, ordinal) : cof (blsub o f) ≤ cardinal.lift.{v u} (o.card)
by { convert cof_lsub_le_lift _, exact (mk_ordinal_out o).symm }
theorem
ordinal.cof_blsub_le_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_blsub_le {o} (f : Π a < o, ordinal) : cof (blsub.{u u} o f) ≤ o.card
by { rw ←(o.card).lift_id, exact cof_blsub_le_lift f }
theorem
ordinal.cof_blsub_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
blsub_lt_ord_lift {o : ordinal} {f : Π a < o, ordinal} {c : ordinal} (ho : o.card.lift < c.cof) (hf : ∀ i hi, f i hi < c) : blsub.{u v} o f < c
lt_of_le_of_ne (blsub_le hf) (λ h, ho.not_le (by simpa [←supr_ord, hf, h] using cof_blsub_le_lift.{u} f))
theorem
ordinal.blsub_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
blsub_lt_ord {o : ordinal} {f : Π a < o, ordinal} {c : ordinal} (ho : o.card < c.cof) (hf : ∀ i hi, f i hi < c) : blsub.{u u} o f < c
blsub_lt_ord_lift (by rwa (o.card).lift_id) hf
theorem
ordinal.blsub_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_bsup_le_lift {o : ordinal} {f : Π a < o, ordinal} (H : ∀ i h, f i h < bsup o f) : cof (bsup o f) ≤ o.card.lift
by { rw ←bsup_eq_blsub_iff_lt_bsup at H, rw H, exact cof_blsub_le_lift f }
theorem
ordinal.cof_bsup_le_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_bsup_le {o : ordinal} {f : Π a < o, ordinal} : (∀ i h, f i h < bsup.{u u} o f) → cof (bsup.{u u} o f) ≤ o.card
by { rw ←(o.card).lift_id, exact cof_bsup_le_lift }
theorem
ordinal.cof_bsup_le
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bsup_lt_ord_lift {o : ordinal} {f : Π a < o, ordinal} {c : ordinal} (ho : o.card.lift < c.cof) (hf : ∀ i hi, f i hi < c) : bsup.{u v} o f < c
(bsup_le_blsub f).trans_lt (blsub_lt_ord_lift ho hf)
theorem
ordinal.bsup_lt_ord_lift
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bsup_lt_ord {o : ordinal} {f : Π a < o, ordinal} {c : ordinal} (ho : o.card < c.cof) : (∀ i hi, f i hi < c) → bsup.{u u} o f < c
bsup_lt_ord_lift (by rwa (o.card).lift_id)
theorem
ordinal.bsup_lt_ord
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_zero : cof 0 = 0
(cof_le_card 0).antisymm (cardinal.zero_le _)
theorem
ordinal.cof_zero
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_eq_zero {o} : cof o = 0 ↔ o = 0
⟨induction_on o $ λ α r _ z, by exactI let ⟨S, hl, e⟩ := cof_eq r in type_eq_zero_iff_is_empty.2 $ ⟨λ a, let ⟨b, h, _⟩ := hl a in (mk_eq_zero_iff.1 (e.trans z)).elim' ⟨_, h⟩⟩, λ e, by simp [e]⟩
theorem
ordinal.cof_eq_zero
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_ne_zero {o} : cof o ≠ 0 ↔ o ≠ 0
cof_eq_zero.not
theorem
ordinal.cof_ne_zero
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_succ (o) : cof (succ o) = 1
begin apply le_antisymm, { refine induction_on o (λ α r _, _), change cof (type _) ≤ _, rw [← (_ : #_ = 1)], apply cof_type_le, { refine λ a, ⟨sum.inr punit.star, set.mem_singleton _, _⟩, rcases a with a|⟨⟨⟨⟩⟩⟩; simp [empty_relation] }, { rw [cardinal.mk_fintype, set.card_singleton], simp } },...
theorem
ordinal.cof_succ
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "cardinal.mk_fintype", "cardinal.succ_zero", "cardinal.zero_le", "lt_iff_le_and_ne", "set.card_singleton", "set.mem_singleton" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_eq_one_iff_is_succ {o} : cof.{u} o = 1 ↔ ∃ a, o = succ a
⟨induction_on o $ λ α r _ z, begin resetI, rcases cof_eq r with ⟨S, hl, e⟩, rw z at e, cases mk_ne_zero_iff.1 (by rw e; exact one_ne_zero) with a, refine ⟨typein r a, eq.symm $ quotient.sound ⟨rel_iso.of_surjective (rel_embedding.of_monotone _ (λ x y, _)) (λ x, _)⟩⟩, { apply sum.rec; [exact subtype....
theorem
ordinal.cof_eq_one_iff_is_succ
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "one_ne_zero", "order.preimage", "rel_embedding.of_monotone", "subrel" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_fundamental_sequence (a o : ordinal.{u}) (f : Π b < o, ordinal.{u}) : Prop
o ≤ a.cof.ord ∧ (∀ {i j} (hi hj), i < j → f i hi < f j hj) ∧ blsub.{u u} o f = a
def
ordinal.is_fundamental_sequence
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
A fundamental sequence for `a` is an increasing sequence of length `o = cof a` that converges at `a`. We provide `o` explicitly in order to avoid type rewrites.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
cof_eq (hf : is_fundamental_sequence a o f) : a.cof.ord = o
hf.1.antisymm' $ by { rw ←hf.2.2, exact (ord_le_ord.2 (cof_blsub_le f)).trans (ord_card_le o) }
theorem
ordinal.is_fundamental_sequence.cof_eq
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
strict_mono (hf : is_fundamental_sequence a o f) {i j} : ∀ hi hj, i < j → f i hi < f j hj
hf.2.1
theorem
ordinal.is_fundamental_sequence.strict_mono
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[ "strict_mono" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
blsub_eq (hf : is_fundamental_sequence a o f) : blsub.{u u} o f = a
hf.2.2
theorem
ordinal.is_fundamental_sequence.blsub_eq
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ord_cof (hf : is_fundamental_sequence a o f) : is_fundamental_sequence a a.cof.ord (λ i hi, f i (hi.trans_le (by rw hf.cof_eq)))
by { have H := hf.cof_eq, subst H, exact hf }
theorem
ordinal.is_fundamental_sequence.ord_cof
set_theory.cardinal
src/set_theory/cardinal/cofinality.lean
[ "set_theory.cardinal.ordinal", "set_theory.ordinal.fixed_point" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83