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sub_sub (a b c : ordinal) : a - b - c = a - (b + c)
eq_of_forall_ge_iff $ λ d, by rw [sub_le, sub_le, sub_le, add_assoc]
theorem
ordinal.sub_sub
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "eq_of_forall_ge_iff", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_sub_add_cancel (a b c : ordinal) : a + b - (a + c) = b - c
by rw [← sub_sub, add_sub_cancel]
theorem
ordinal.add_sub_add_cancel
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sub_is_limit {a b} (l : is_limit a) (h : b < a) : is_limit (a - b)
⟨ne_of_gt $ lt_sub.2 $ by rwa add_zero, λ c h, by rw [lt_sub, add_succ]; exact l.2 _ (lt_sub.1 h)⟩
theorem
ordinal.sub_is_limit
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_add_omega : 1 + ω = ω
begin refine le_antisymm _ (le_add_left _ _), rw [omega, ← lift_one.{0}, ← lift_add, lift_le, ← type_unit, ← type_sum_lex], refine ⟨rel_embedding.collapse (rel_embedding.of_monotone _ _)⟩, { apply sum.rec, exact λ _, 0, exact nat.succ }, { intros a b, cases a; cases b; intro H; cases H with _ _ H _ _ H; [...
theorem
ordinal.one_add_omega
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "rel_embedding.of_monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_add_of_omega_le {o} (h : ω ≤ o) : 1 + o = o
by rw [← ordinal.add_sub_cancel_of_le h, ← add_assoc, one_add_omega]
theorem
ordinal.one_add_of_omega_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal.add_sub_cancel_of_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
type_prod_lex {α β : Type u} (r : α → α → Prop) (s : β → β → Prop) [is_well_order α r] [is_well_order β s] : type (prod.lex s r) = type r * type s
rfl
theorem
ordinal.type_prod_lex
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_eq_zero' {a b : ordinal} : a * b = 0 ↔ a = 0 ∨ b = 0
induction_on a $ λ α _ _, induction_on b $ λ β _ _, begin simp_rw [←type_prod_lex, type_eq_zero_iff_is_empty], rw or_comm, exact is_empty_prod end
theorem
ordinal.mul_eq_zero'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_empty_prod", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lift_mul (a b) : lift (a * b) = lift a * lift b
quotient.induction_on₂ a b $ λ ⟨α, r, _⟩ ⟨β, s, _⟩, quotient.sound ⟨(rel_iso.preimage equiv.ulift _).trans (rel_iso.prod_lex_congr (rel_iso.preimage equiv.ulift _) (rel_iso.preimage equiv.ulift _)).symm⟩
theorem
ordinal.lift_mul
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "equiv.ulift", "lift", "rel_iso.preimage", "rel_iso.prod_lex_congr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
card_mul (a b) : card (a * b) = card a * card b
quotient.induction_on₂ a b $ λ ⟨α, r, _⟩ ⟨β, s, _⟩, mul_comm (mk β) (mk α)
theorem
ordinal.card_mul
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_comm" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_succ (a b : ordinal) : a * succ b = a * b + a
mul_add_one a b
theorem
ordinal.mul_succ
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_add_one", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_covariant_class_le : covariant_class ordinal.{u} ordinal.{u} (*) (≤)
⟨λ c a b, quotient.induction_on₃ a b c $ λ ⟨α, r, _⟩ ⟨β, s, _⟩ ⟨γ, t, _⟩ ⟨f⟩, begin resetI, refine (rel_embedding.of_monotone (λ a : α × γ, (f a.1, a.2)) (λ a b h, _)).ordinal_type_le, clear_, cases h with a₁ b₁ a₂ b₂ h' a b₁ b₂ h', { exact prod.lex.left _ _ (f.to_rel_embedding.map_rel_iff.2 h') }, { exact ...
instance
ordinal.mul_covariant_class_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "covariant_class", "rel_embedding.of_monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_swap_covariant_class_le : covariant_class ordinal.{u} ordinal.{u} (swap (*)) (≤)
⟨λ c a b, quotient.induction_on₃ a b c $ λ ⟨α, r, _⟩ ⟨β, s, _⟩ ⟨γ, t, _⟩ ⟨f⟩, begin resetI, refine (rel_embedding.of_monotone (λ a : γ × α, (a.1, f a.2)) (λ a b h, _)).ordinal_type_le, cases h with a₁ b₁ a₂ b₂ h' a b₁ b₂ h', { exact prod.lex.left _ _ h' }, { exact prod.lex.right _ (f.to_rel_embedding.map_rel_...
instance
ordinal.mul_swap_covariant_class_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "covariant_class", "rel_embedding.of_monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mul_left (a : ordinal) {b : ordinal} (hb : 0 < b) : a ≤ a * b
by { convert mul_le_mul_left' (one_le_iff_pos.2 hb) a, rw mul_one a }
theorem
ordinal.le_mul_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "le_mul_left", "mul_le_mul_left'", "mul_one", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_mul_right (a : ordinal) {b : ordinal} (hb : 0 < b) : a ≤ b * a
by { convert mul_le_mul_right' (one_le_iff_pos.2 hb) a, rw one_mul a }
theorem
ordinal.le_mul_right
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "le_mul_right", "mul_le_mul_right'", "one_mul", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_le_of_limit_aux {α β r s} [is_well_order α r] [is_well_order β s] {c} (h : is_limit (type s)) (H : ∀ b' < type s, type r * b' ≤ c) (l : c < type r * type s) : false
begin suffices : ∀ a b, prod.lex s r (b, a) (enum _ _ l), { cases enum _ _ l with b a, exact irrefl _ (this _ _) }, intros a b, rw [←typein_lt_typein (prod.lex s r), typein_enum], have := H _ (h.2 _ (typein_lt_type s b)), rw mul_succ at this, have := ((add_lt_add_iff_left _).2 (typein_lt_type _ a)).trans_...
lemma
ordinal.mul_le_of_limit_aux
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order", "prod.lex_def", "rel_embedding.of_monotone", "subrel_val", "subtype.mk_eq_mk", "sum.lex_inl_inl", "sum.lex_inr_inl", "sum.lex_inr_inr" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_le_of_limit {a b c : ordinal} (h : is_limit b) : a * b ≤ c ↔ ∀ b' < b, a * b' ≤ c
⟨λ h b' l, (mul_le_mul_left' l.le _).trans h, λ H, le_of_not_lt $ induction_on a (λ α r _, induction_on b $ λ β s _, by exactI mul_le_of_limit_aux) h H⟩
theorem
ordinal.mul_le_of_limit
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_le_mul_left'", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_is_normal {a : ordinal} (h : 0 < a) : is_normal ((*) a)
⟨λ b, by rw mul_succ; simpa only [add_zero] using (add_lt_add_iff_left (a*b)).2 h, λ b l c, mul_le_of_limit l⟩
theorem
ordinal.mul_is_normal
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_mul_of_limit {a b c : ordinal} (h : is_limit c) : a < b * c ↔ ∃ c' < c, a < b * c'
by simpa only [not_ball, not_le] using not_congr (@mul_le_of_limit b c a h)
theorem
ordinal.lt_mul_of_limit
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "not_ball", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_lt_mul_iff_left {a b c : ordinal} (a0 : 0 < a) : a * b < a * c ↔ b < c
(mul_is_normal a0).lt_iff
theorem
ordinal.mul_lt_mul_iff_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_lt_mul_iff_left", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_le_mul_iff_left {a b c : ordinal} (a0 : 0 < a) : a * b ≤ a * c ↔ b ≤ c
(mul_is_normal a0).le_iff
theorem
ordinal.mul_le_mul_iff_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_le_mul_iff_left", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_lt_mul_of_pos_left {a b c : ordinal} (h : a < b) (c0 : 0 < c) : c * a < c * b
(mul_lt_mul_iff_left c0).2 h
theorem
ordinal.mul_lt_mul_of_pos_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_lt_mul_iff_left", "mul_lt_mul_of_pos_left", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_pos {a b : ordinal} (h₁ : 0 < a) (h₂ : 0 < b) : 0 < a * b
by simpa only [mul_zero] using mul_lt_mul_of_pos_left h₂ h₁
theorem
ordinal.mul_pos
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_lt_mul_of_pos_left", "mul_zero", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_ne_zero {a b : ordinal} : a ≠ 0 → b ≠ 0 → a * b ≠ 0
by simpa only [ordinal.pos_iff_ne_zero] using mul_pos
theorem
ordinal.mul_ne_zero
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_ne_zero", "ordinal", "ordinal.pos_iff_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_of_mul_le_mul_left {a b c : ordinal} (h : c * a ≤ c * b) (h0 : 0 < c) : a ≤ b
le_imp_le_of_lt_imp_lt (λ h', mul_lt_mul_of_pos_left h' h0) h
theorem
ordinal.le_of_mul_le_mul_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "le_of_mul_le_mul_left", "mul_lt_mul_of_pos_left", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_right_inj {a b c : ordinal} (a0 : 0 < a) : a * b = a * c ↔ b = c
(mul_is_normal a0).inj
theorem
ordinal.mul_right_inj
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_right_inj", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_is_limit {a b : ordinal} (a0 : 0 < a) : is_limit b → is_limit (a * b)
(mul_is_normal a0).is_limit
theorem
ordinal.mul_is_limit
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_is_limit_left {a b : ordinal} (l : is_limit a) (b0 : 0 < b) : is_limit (a * b)
begin rcases zero_or_succ_or_limit b with rfl|⟨b,rfl⟩|lb, { exact b0.false.elim }, { rw mul_succ, exact add_is_limit _ l }, { exact mul_is_limit l.pos lb } end
theorem
ordinal.mul_is_limit_left
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
smul_eq_mul : ∀ (n : ℕ) (a : ordinal), n • a = a * n
| 0 a := by rw [zero_smul, nat.cast_zero, mul_zero] | (n + 1) a := by rw [succ_nsmul', nat.cast_add, mul_add, nat.cast_one, mul_one, smul_eq_mul]
theorem
ordinal.smul_eq_mul
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_one", "mul_zero", "nat.cast_add", "nat.cast_one", "nat.cast_zero", "ordinal", "smul_eq_mul", "zero_smul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_nonempty {a b : ordinal} (h : b ≠ 0) : {o | a < b * succ o}.nonempty
⟨a, succ_le_iff.1 $ by simpa only [succ_zero, one_mul] using mul_le_mul_right' (succ_le_of_lt (ordinal.pos_iff_ne_zero.2 h)) (succ a)⟩
theorem
ordinal.div_nonempty
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_le_mul_right'", "one_mul", "ordinal" ]
The set in the definition of division is nonempty.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_zero (a : ordinal) : a / 0 = 0
dif_pos rfl
theorem
ordinal.div_zero
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_zero", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_def (a) {b : ordinal} (h : b ≠ 0) : a / b = Inf {o | a < b * succ o}
dif_neg h
lemma
ordinal.div_def
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_mul_succ_div (a) {b : ordinal} (h : b ≠ 0) : a < b * succ (a / b)
by rw div_def a h; exact Inf_mem (div_nonempty h)
theorem
ordinal.lt_mul_succ_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "Inf_mem", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_mul_div_add (a) {b : ordinal} (h : b ≠ 0) : a < b * (a / b) + b
by simpa only [mul_succ] using lt_mul_succ_div a h
theorem
ordinal.lt_mul_div_add
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_le {a b c : ordinal} (b0 : b ≠ 0) : a / b ≤ c ↔ a < b * succ c
⟨λ h, (lt_mul_succ_div a b0).trans_le (mul_le_mul_left' (succ_le_succ_iff.2 h) _), λ h, by rw div_def a b0; exact cInf_le' h⟩
theorem
ordinal.div_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "cInf_le'", "mul_le_mul_left'", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_div {a b c : ordinal} (h : c ≠ 0) : a < b / c ↔ c * succ a ≤ b
by rw [← not_le, div_le h, not_lt]
theorem
ordinal.lt_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_pos {b c : ordinal} (h : c ≠ 0) : 0 < b / c ↔ c ≤ b
by simp [lt_div h]
theorem
ordinal.div_pos
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_pos", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_div {a b c : ordinal} (c0 : c ≠ 0) : a ≤ b / c ↔ c * a ≤ b
begin apply limit_rec_on a, { simp only [mul_zero, ordinal.zero_le] }, { intros, rw [succ_le_iff, lt_div c0] }, { simp only [mul_le_of_limit, limit_le, iff_self, forall_true_iff] {contextual := tt} } end
theorem
ordinal.le_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "forall_true_iff", "mul_zero", "ordinal", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_lt {a b c : ordinal} (b0 : b ≠ 0) : a / b < c ↔ a < b * c
lt_iff_lt_of_le_iff_le $ le_div b0
theorem
ordinal.div_lt
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "lt_iff_lt_of_le_iff_le", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_le_of_le_mul {a b c : ordinal} (h : a ≤ b * c) : a / b ≤ c
if b0 : b = 0 then by simp only [b0, div_zero, ordinal.zero_le] else (div_le b0).2 $ h.trans_lt $ mul_lt_mul_of_pos_left (lt_succ c) (ordinal.pos_iff_ne_zero.2 b0)
theorem
ordinal.div_le_of_le_mul
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_zero", "mul_lt_mul_of_pos_left", "ordinal", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_lt_of_lt_div {a b c : ordinal} : a < b / c → c * a < b
lt_imp_lt_of_le_imp_le div_le_of_le_mul
theorem
ordinal.mul_lt_of_lt_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "lt_imp_lt_of_le_imp_le", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_div (a : ordinal) : 0 / a = 0
ordinal.le_zero.1 $ div_le_of_le_mul $ ordinal.zero_le _
theorem
ordinal.zero_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "ordinal.zero_le", "zero_div" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_div_le (a b : ordinal) : b * (a / b) ≤ a
if b0 : b = 0 then by simp only [b0, zero_mul, ordinal.zero_le] else (le_div b0).1 le_rfl
theorem
ordinal.mul_div_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "le_rfl", "ordinal", "ordinal.zero_le", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_add_div (a) {b : ordinal} (b0 : b ≠ 0) (c) : (b * a + c) / b = a + c / b
begin apply le_antisymm, { apply (div_le b0).2, rw [mul_succ, mul_add, add_assoc, add_lt_add_iff_left], apply lt_mul_div_add _ b0 }, { rw [le_div b0, mul_add, add_le_add_iff_left], apply mul_div_le } end
theorem
ordinal.mul_add_div
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_eq_zero_of_lt {a b : ordinal} (h : a < b) : a / b = 0
begin rw [←ordinal.le_zero, div_le $ ordinal.pos_iff_ne_zero.1 $ (ordinal.zero_le _).trans_lt h], simpa only [succ_zero, mul_one] using h end
theorem
ordinal.div_eq_zero_of_lt
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_one", "ordinal", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_div_cancel (a) {b : ordinal} (b0 : b ≠ 0) : b * a / b = a
by simpa only [add_zero, zero_div] using mul_add_div a b0 0
theorem
ordinal.mul_div_cancel
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_div_cancel", "ordinal", "zero_div" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_one (a : ordinal) : a / 1 = a
by simpa only [one_mul] using mul_div_cancel a ordinal.one_ne_zero
theorem
ordinal.div_one
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_one", "mul_div_cancel", "one_mul", "ordinal", "ordinal.one_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_self {a : ordinal} (h : a ≠ 0) : a / a = 1
by simpa only [mul_one] using mul_div_cancel 1 h
theorem
ordinal.div_self
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_self", "mul_div_cancel", "mul_one", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_sub (a b c : ordinal) : a * (b - c) = a * b - a * c
if a0 : a = 0 then by simp only [a0, zero_mul, sub_self] else eq_of_forall_ge_iff $ λ d, by rw [sub_le, ← le_div a0, sub_le, ← le_div a0, mul_add_div _ a0]
theorem
ordinal.mul_sub
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "eq_of_forall_ge_iff", "ordinal", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_limit_add_iff {a b} : is_limit (a + b) ↔ is_limit b ∨ (b = 0 ∧ is_limit a)
begin split; intro h, { by_cases h' : b = 0, { rw [h', add_zero] at h, right, exact ⟨h', h⟩ }, left, rw [←add_sub_cancel a b], apply sub_is_limit h, suffices : a + 0 < a + b, simpa only [add_zero], rwa [add_lt_add_iff_left, ordinal.pos_iff_ne_zero] }, rcases h with h|⟨rfl, h⟩, exact add_is_l...
theorem
ordinal.is_limit_add_iff
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal.pos_iff_ne_zero" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dvd_add_iff : ∀ {a b c : ordinal}, a ∣ b → (a ∣ b + c ↔ a ∣ c)
| a _ c ⟨b, rfl⟩ := ⟨λ ⟨d, e⟩, ⟨d - b, by rw [mul_sub, ← e, add_sub_cancel]⟩, λ ⟨d, e⟩, by { rw [e, ← mul_add], apply dvd_mul_right }⟩
theorem
ordinal.dvd_add_iff
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "dvd_mul_right", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_mul_cancel : ∀ {a b : ordinal}, a ≠ 0 → a ∣ b → a * (b / a) = b
| a _ a0 ⟨b, rfl⟩ := by rw [mul_div_cancel _ a0]
theorem
ordinal.div_mul_cancel
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_mul_cancel", "mul_div_cancel", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_of_dvd : ∀ {a b : ordinal}, b ≠ 0 → a ∣ b → a ≤ b
| a _ b0 ⟨b, rfl⟩ := by simpa only [mul_one] using mul_le_mul_left' (one_le_iff_ne_zero.2 (λ h : b = 0, by simpa only [h, mul_zero] using b0)) a
theorem
ordinal.le_of_dvd
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_le_mul_left'", "mul_one", "mul_zero", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dvd_antisymm {a b : ordinal} (h₁ : a ∣ b) (h₂ : b ∣ a) : a = b
if a0 : a = 0 then by subst a; exact (eq_zero_of_zero_dvd h₁).symm else if b0 : b = 0 then by subst b; exact eq_zero_of_zero_dvd h₂ else (le_of_dvd b0 h₁).antisymm (le_of_dvd a0 h₂)
theorem
ordinal.dvd_antisymm
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "dvd_antisymm", "eq_zero_of_zero_dvd", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_def (a b : ordinal) : a % b = a - b * (a / b)
rfl
theorem
ordinal.mod_def
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_le (a b : ordinal) : a % b ≤ a
sub_le_self a _
theorem
ordinal.mod_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_zero (a : ordinal) : a % 0 = a
by simp only [mod_def, div_zero, zero_mul, sub_zero]
theorem
ordinal.mod_zero
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_zero", "ordinal", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_eq_of_lt {a b : ordinal} (h : a < b) : a % b = a
by simp only [mod_def, div_eq_zero_of_lt h, mul_zero, sub_zero]
theorem
ordinal.mod_eq_of_lt
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_zero", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_mod (b : ordinal) : 0 % b = 0
by simp only [mod_def, zero_div, mul_zero, sub_self]
theorem
ordinal.zero_mod
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_zero", "ordinal", "zero_div" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
div_add_mod (a b : ordinal) : b * (a / b) + a % b = a
ordinal.add_sub_cancel_of_le $ mul_div_le _ _
theorem
ordinal.div_add_mod
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "ordinal.add_sub_cancel_of_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_lt (a) {b : ordinal} (h : b ≠ 0) : a % b < b
(add_lt_add_iff_left (b * (a / b))).1 $ by rw div_add_mod; exact lt_mul_div_add a h
theorem
ordinal.mod_lt
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_self (a : ordinal) : a % a = 0
if a0 : a = 0 then by simp only [a0, zero_mod] else by simp only [mod_def, div_self a0, mul_one, sub_self]
theorem
ordinal.mod_self
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_self", "mul_one", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_one (a : ordinal) : a % 1 = 0
by simp only [mod_def, div_one, one_mul, sub_self]
theorem
ordinal.mod_one
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "div_one", "one_mul", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dvd_of_mod_eq_zero {a b : ordinal} (H : a % b = 0) : b ∣ a
⟨a / b, by simpa [H] using (div_add_mod a b).symm⟩
theorem
ordinal.dvd_of_mod_eq_zero
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_eq_zero_of_dvd {a b : ordinal} (H : b ∣ a) : a % b = 0
begin rcases H with ⟨c, rfl⟩, rcases eq_or_ne b 0 with rfl | hb, { simp }, { simp [mod_def, hb] } end
theorem
ordinal.mod_eq_zero_of_dvd
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "eq_or_ne", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
dvd_iff_mod_eq_zero {a b : ordinal} : b ∣ a ↔ a % b = 0
⟨mod_eq_zero_of_dvd, dvd_of_mod_eq_zero⟩
theorem
ordinal.dvd_iff_mod_eq_zero
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_add_mod_self (x y z : ordinal) : (x * y + z) % x = z % x
begin rcases eq_or_ne x 0 with rfl | hx, { simp }, { rwa [mod_def, mul_add_div, mul_add, ←sub_sub, add_sub_cancel, mod_def] } end
theorem
ordinal.mul_add_mod_self
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "eq_or_ne", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_mod (x y : ordinal) : x * y % x = 0
by simpa using mul_add_mod_self x y 0
theorem
ordinal.mul_mod
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_mod_of_dvd (a : ordinal) {b c : ordinal} (h : c ∣ b) : a % b % c = a % c
begin nth_rewrite_rhs 0 ←div_add_mod a b, rcases h with ⟨d, rfl⟩, rw [mul_assoc, mul_add_mod_self] end
theorem
ordinal.mod_mod_of_dvd
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "mul_assoc", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mod_mod (a b : ordinal) : a % b % b = a % b
mod_mod_of_dvd a dvd_rfl
theorem
ordinal.mod_mod
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "dvd_rfl", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bfamily_of_family' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] (f : ι → α) : Π a < type r, α
λ a ha, f (enum r a ha)
def
ordinal.bfamily_of_family'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
Converts a family indexed by a `Type u` to one indexed by an `ordinal.{u}` using a specified well-ordering.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bfamily_of_family {ι : Type u} : (ι → α) → Π a < type (@well_ordering_rel ι), α
bfamily_of_family' well_ordering_rel
def
ordinal.bfamily_of_family
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "well_ordering_rel" ]
Converts a family indexed by a `Type u` to one indexed by an `ordinal.{u}` using a well-ordering given by the axiom of choice.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
family_of_bfamily' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] {o} (ho : type r = o) (f : Π a < o, α) : ι → α
λ i, f (typein r i) (by { rw ←ho, exact typein_lt_type r i })
def
ordinal.family_of_bfamily'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
Converts a family indexed by an `ordinal.{u}` to one indexed by an `Type u` using a specified well-ordering.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
family_of_bfamily (o : ordinal) (f : Π a < o, α) : o.out.α → α
family_of_bfamily' (<) (type_lt o) f
def
ordinal.family_of_bfamily
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
Converts a family indexed by an `ordinal.{u}` to one indexed by a `Type u` using a well-ordering given by the axiom of choice.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bfamily_of_family'_typein {ι} (r : ι → ι → Prop) [is_well_order ι r] (f : ι → α) (i) : bfamily_of_family' r f (typein r i) (typein_lt_type r i) = f i
by simp only [bfamily_of_family', enum_typein]
theorem
ordinal.bfamily_of_family'_typein
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bfamily_of_family_typein {ι} (f : ι → α) (i) : bfamily_of_family f (typein _ i) (typein_lt_type _ i) = f i
bfamily_of_family'_typein _ f i
theorem
ordinal.bfamily_of_family_typein
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
family_of_bfamily'_enum {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] {o} (ho : type r = o) (f : Π a < o, α) (i hi) : family_of_bfamily' r ho f (enum r i (by rwa ho)) = f i hi
by simp only [family_of_bfamily', typein_enum]
theorem
ordinal.family_of_bfamily'_enum
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
family_of_bfamily_enum (o : ordinal) (f : Π a < o, α) (i hi) : family_of_bfamily o f (enum (<) i (by { convert hi, exact type_lt _ })) = f i hi
family_of_bfamily'_enum _ (type_lt o) f _ _
theorem
ordinal.family_of_bfamily_enum
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
brange (o : ordinal) (f : Π a < o, α) : set α
{a | ∃ i hi, f i hi = a}
def
ordinal.brange
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
The range of a family indexed by ordinals.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_brange {o : ordinal} {f : Π a < o, α} {a} : a ∈ brange o f ↔ ∃ i hi, f i hi = a
iff.rfl
theorem
ordinal.mem_brange
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mem_brange_self {o} (f : Π a < o, α) (i hi) : f i hi ∈ brange o f
⟨i, hi, rfl⟩
theorem
ordinal.mem_brange_self
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_family_of_bfamily' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] {o} (ho : type r = o) (f : Π a < o, α) : range (family_of_bfamily' r ho f) = brange o f
begin refine set.ext (λ a, ⟨_, _⟩), { rintro ⟨b, rfl⟩, apply mem_brange_self }, { rintro ⟨i, hi, rfl⟩, exact ⟨_, family_of_bfamily'_enum _ _ _ _ _⟩ } end
theorem
ordinal.range_family_of_bfamily'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
range_family_of_bfamily {o} (f : Π a < o, α) : range (family_of_bfamily o f) = brange o f
range_family_of_bfamily' _ _ f
theorem
ordinal.range_family_of_bfamily
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
brange_bfamily_of_family' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] (f : ι → α) : brange _ (bfamily_of_family' r f) = range f
begin refine set.ext (λ a, ⟨_, _⟩), { rintro ⟨i, hi, rfl⟩, apply mem_range_self }, { rintro ⟨b, rfl⟩, exact ⟨_, _, bfamily_of_family'_typein _ _ _⟩ }, end
theorem
ordinal.brange_bfamily_of_family'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order", "set.ext" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
brange_bfamily_of_family {ι : Type u} (f : ι → α) : brange _ (bfamily_of_family f) = range f
brange_bfamily_of_family' _ _
theorem
ordinal.brange_bfamily_of_family
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
brange_const {o : ordinal} (ho : o ≠ 0) {c : α} : brange o (λ _ _, c) = {c}
begin rw ←range_family_of_bfamily, exact @set.range_const _ o.out.α (out_nonempty_iff_ne_zero.2 ho) c end
theorem
ordinal.brange_const
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "set.range_const" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_bfamily_of_family' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] (f : ι → α) (g : α → β) : (λ i hi, g (bfamily_of_family' r f i hi)) = bfamily_of_family' r (g ∘ f)
rfl
theorem
ordinal.comp_bfamily_of_family'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_bfamily_of_family {ι : Type u} (f : ι → α) (g : α → β) : (λ i hi, g (bfamily_of_family f i hi)) = bfamily_of_family (g ∘ f)
rfl
theorem
ordinal.comp_bfamily_of_family
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_family_of_bfamily' {ι : Type u} (r : ι → ι → Prop) [is_well_order ι r] {o} (ho : type r = o) (f : Π a < o, α) (g : α → β) : g ∘ (family_of_bfamily' r ho f) = family_of_bfamily' r ho (λ i hi, g (f i hi))
rfl
theorem
ordinal.comp_family_of_bfamily'
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "is_well_order" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
comp_family_of_bfamily {o} (f : Π a < o, α) (g : α → β) : g ∘ (family_of_bfamily o f) = family_of_bfamily o (λ i hi, g (f i hi))
rfl
theorem
ordinal.comp_family_of_bfamily
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup {ι : Type u} (f : ι → ordinal.{max u v}) : ordinal.{max u v}
supr f
def
ordinal.sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "supr" ]
The supremum of a family of ordinals
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
Sup_eq_sup {ι : Type u} (f : ι → ordinal.{max u v}) : Sup (set.range f) = sup f
rfl
theorem
ordinal.Sup_eq_sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "set.range" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
bdd_above_range {ι : Type u} (f : ι → ordinal.{max u v}) : bdd_above (set.range f)
⟨(supr (succ ∘ card ∘ f)).ord, begin rintros a ⟨i, rfl⟩, exact le_of_lt (cardinal.lt_ord.2 ((lt_succ _).trans_le (le_csupr (bdd_above_range _) _))) end⟩
theorem
ordinal.bdd_above_range
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "bdd_above", "le_csupr", "set.range", "supr" ]
The range of an indexed ordinal function, whose outputs live in a higher universe than the inputs, is always bounded above. See `ordinal.lsub` for an explicit bound.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_sup {ι} (f : ι → ordinal) : ∀ i, f i ≤ sup f
λ i, le_cSup (bdd_above_range f) (mem_range_self i)
theorem
ordinal.le_sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "le_cSup", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_le_iff {ι} {f : ι → ordinal} {a} : sup f ≤ a ↔ ∀ i, f i ≤ a
(cSup_le_iff' (bdd_above_range f)).trans (by simp)
theorem
ordinal.sup_le_iff
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "cSup_le_iff'", "ordinal", "sup_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_le {ι} {f : ι → ordinal} {a} : (∀ i, f i ≤ a) → sup f ≤ a
sup_le_iff.2
theorem
ordinal.sup_le
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_sup {ι} {f : ι → ordinal} {a} : a < sup f ↔ ∃ i, a < f i
by simpa only [not_forall, not_le] using not_congr (@sup_le_iff _ f a)
theorem
ordinal.lt_sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "not_forall", "ordinal", "sup_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ne_sup_iff_lt_sup {ι} {f : ι → ordinal} : (∀ i, f i ≠ sup f) ↔ ∀ i, f i < sup f
⟨λ hf _, lt_of_le_of_ne (le_sup _ _) (hf _), λ hf _, ne_of_lt (hf _)⟩
theorem
ordinal.ne_sup_iff_lt_sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_not_succ_of_ne_sup {ι} {f : ι → ordinal} (hf : ∀ i, f i ≠ sup f) {a} (hao : a < sup f) : succ a < sup f
begin by_contra' hoa, exact hao.not_le (sup_le $ λ i, le_of_lt_succ $ (lt_of_le_of_ne (le_sup _ _) (hf i)).trans_le hoa) end
theorem
ordinal.sup_not_succ_of_ne_sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_eq_zero_iff {ι} {f : ι → ordinal} : sup f = 0 ↔ ∀ i, f i = 0
begin refine ⟨λ h i, _, λ h, le_antisymm (sup_le (λ i, ordinal.le_zero.2 (h i))) (ordinal.zero_le _)⟩, rw [←ordinal.le_zero, ←h], exact le_sup f i end
theorem
ordinal.sup_eq_zero_iff
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "ordinal", "ordinal.zero_le", "sup_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.sup {f} (H : is_normal f) {ι} (g : ι → ordinal) [nonempty ι] : f (sup g) = sup (f ∘ g)
eq_of_forall_ge_iff $ λ a, by rw [sup_le_iff, comp, H.le_set' set.univ set.univ_nonempty g]; simp [sup_le_iff]
theorem
ordinal.is_normal.sup
set_theory.ordinal
src/set_theory/ordinal/arithmetic.lean
[ "set_theory.ordinal.basic", "tactic.by_contra" ]
[ "eq_of_forall_ge_iff", "ordinal", "set.univ_nonempty", "sup_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83