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nfp_bfamily_eq_self {a} (h : ∀ i hi, f i hi a = a) : nfp_bfamily o f a = a
nfp_family_eq_self (λ _, h _ _)
theorem
ordinal.nfp_bfamily_eq_self
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fp_bfamily_unbounded (H : ∀ i hi, is_normal (f i hi)) : (⋂ i hi, function.fixed_points (f i hi)).unbounded (<)
λ a, ⟨_, by { rw set.mem_Inter₂, exact λ i hi, nfp_bfamily_fp (H i hi) _ }, (le_nfp_bfamily f a).not_lt⟩
theorem
ordinal.fp_bfamily_unbounded
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "function.fixed_points", "set.mem_Inter₂" ]
A generalization of the fixed point lemma for normal functions: any family of normal functions has an unbounded set of common fixed points.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_bfamily (o : ordinal) (f : Π b < o, ordinal → ordinal) : ordinal → ordinal
deriv_family (family_of_bfamily o f)
def
ordinal.deriv_bfamily
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
The derivative of a family of normal functions is the sequence of their common fixed points. This is defined as `ordinal.deriv_family` of the type-indexed family associated to `f`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_bfamily_eq_deriv_family {o : ordinal} (f : Π b < o, ordinal → ordinal) : deriv_bfamily o f = deriv_family (family_of_bfamily o f)
rfl
theorem
ordinal.deriv_bfamily_eq_deriv_family
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_bfamily_is_normal {o : ordinal} (f : Π b < o, ordinal → ordinal) : is_normal (deriv_bfamily o f)
deriv_family_is_normal _
theorem
ordinal.deriv_bfamily_is_normal
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_bfamily_fp {i hi} (H : is_normal (f i hi)) (a : ordinal) : f i hi (deriv_bfamily o f a) = deriv_bfamily o f a
by { rw ←family_of_bfamily_enum o f, apply deriv_family_fp, rw family_of_bfamily_enum, exact H }
theorem
ordinal.deriv_bfamily_fp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_iff_deriv_bfamily (H : ∀ i hi, is_normal (f i hi)) {a} : (∀ i hi, f i hi a ≤ a) ↔ ∃ b, deriv_bfamily o f b = a
begin unfold deriv_bfamily, rw ←le_iff_deriv_family, { refine ⟨λ h i, h _ _, λ h i hi, _⟩, rw ←family_of_bfamily_enum o f, apply h }, { exact λ _, H _ _ } end
theorem
ordinal.le_iff_deriv_bfamily
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fp_iff_deriv_bfamily (H : ∀ i hi, is_normal (f i hi)) {a} : (∀ i hi, f i hi a = a) ↔ ∃ b, deriv_bfamily o f b = a
begin rw ←le_iff_deriv_bfamily H, refine ⟨λ h i hi, le_of_eq (h i hi), λ h i hi, _⟩, rw ←(H i hi).le_iff_eq, exact h i hi end
theorem
ordinal.fp_iff_deriv_bfamily
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_bfamily_eq_enum_ord (H : ∀ i hi, is_normal (f i hi)) : deriv_bfamily o f = enum_ord (⋂ i hi, function.fixed_points (f i hi))
begin rw ←eq_enum_ord _ (fp_bfamily_unbounded H), use (deriv_bfamily_is_normal f).strict_mono, rw set.range_eq_iff, refine ⟨λ a, set.mem_Inter₂.2 (λ i hi, deriv_bfamily_fp (H i hi) a), λ a ha, _⟩, rw set.mem_Inter₂ at ha, rwa ←fp_iff_deriv_bfamily H end
theorem
ordinal.deriv_bfamily_eq_enum_ord
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "function.fixed_points", "set.mem_Inter₂", "set.range_eq_iff", "strict_mono" ]
For a family of normal functions, `ordinal.deriv_bfamily` enumerates the common fixed points.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp (f : ordinal → ordinal) : ordinal → ordinal
nfp_family (λ _ : unit, f)
def
ordinal.nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
The next fixed point function, the least fixed point of the normal function `f`, at least `a`. This is defined as `ordinal.nfp_family` applied to a family consisting only of `f`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_eq_nfp_family (f : ordinal → ordinal) : nfp f = nfp_family (λ _ : unit, f)
rfl
theorem
ordinal.nfp_eq_nfp_family
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
sup_iterate_eq_nfp (f : ordinal.{u} → ordinal.{u}) : (λ a, sup (λ n : ℕ, f^[n] a)) = nfp f
begin refine funext (λ a, le_antisymm _ (sup_le (λ l, _))), { rw sup_le_iff, intro n, rw [←list.length_replicate n unit.star, ←list.foldr_const f a], apply le_sup }, { rw list.foldr_const f a l, exact le_sup _ _ }, end
theorem
ordinal.sup_iterate_eq_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "list.foldr_const", "sup_le", "sup_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
iterate_le_nfp (f a n) : f^[n] a ≤ nfp f a
by { rw ←sup_iterate_eq_nfp, exact le_sup _ n }
theorem
ordinal.iterate_le_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
le_nfp (f a) : a ≤ nfp f a
iterate_le_nfp f a 0
theorem
ordinal.le_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_nfp {a b} : a < nfp f b ↔ ∃ n, a < (f^[n]) b
by { rw ←sup_iterate_eq_nfp, exact lt_sup }
theorem
ordinal.lt_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_le_iff {a b} : nfp f a ≤ b ↔ ∀ n, (f^[n]) a ≤ b
by { rw ←sup_iterate_eq_nfp, exact sup_le_iff }
theorem
ordinal.nfp_le_iff
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "sup_le_iff" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_le {a b} : (∀ n, (f^[n]) a ≤ b) → nfp f a ≤ b
nfp_le_iff.2
theorem
ordinal.nfp_le
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_id : nfp id = id
funext (λ a, begin simp_rw [←sup_iterate_eq_nfp, iterate_id], exact sup_const a end)
theorem
ordinal.nfp_id
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_monotone (hf : monotone f) : monotone (nfp f)
nfp_family_monotone (λ i, hf)
theorem
ordinal.nfp_monotone
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.apply_lt_nfp {f} (H : is_normal f) {a b} : f b < nfp f a ↔ b < nfp f a
begin unfold nfp, rw ←@apply_lt_nfp_family_iff unit (λ _, f) _ (λ _, H) a b, exact ⟨λ h _, h, λ h, h unit.star⟩ end
theorem
ordinal.is_normal.apply_lt_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.nfp_le_apply {f} (H : is_normal f) {a b} : nfp f a ≤ f b ↔ nfp f a ≤ b
le_iff_le_iff_lt_iff_lt.2 H.apply_lt_nfp
theorem
ordinal.is_normal.nfp_le_apply
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_le_fp {f} (H : monotone f) {a b} (ab : a ≤ b) (h : f b ≤ b) : nfp f a ≤ b
nfp_family_le_fp (λ _, H) ab (λ _, h)
theorem
ordinal.nfp_le_fp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.nfp_fp {f} (H : is_normal f) : ∀ a, f (nfp f a) = nfp f a
@nfp_family_fp unit (λ _, f) unit.star H
theorem
ordinal.is_normal.nfp_fp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.apply_le_nfp {f} (H : is_normal f) {a b} : f b ≤ nfp f a ↔ b ≤ nfp f a
⟨le_trans (H.self_le _), λ h, by simpa only [H.nfp_fp] using H.le_iff.2 h⟩
theorem
ordinal.is_normal.apply_le_nfp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_eq_self {f : ordinal → ordinal} {a} (h : f a = a) : nfp f a = a
nfp_family_eq_self (λ _, h)
theorem
ordinal.nfp_eq_self
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
fp_unbounded (H : is_normal f) : (function.fixed_points f).unbounded (<)
by { convert fp_family_unbounded (λ _ : unit, H), exact (set.Inter_const _).symm }
theorem
ordinal.fp_unbounded
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "function.fixed_points", "set.Inter_const" ]
The fixed point lemma for normal functions: any normal function has an unbounded set of fixed points.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv (f : ordinal → ordinal) : ordinal → ordinal
deriv_family (λ _ : unit, f)
def
ordinal.deriv
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "ordinal" ]
The derivative of a normal function `f` is the sequence of fixed points of `f`. This is defined as `ordinal.deriv_family` applied to a trivial family consisting only of `f`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_eq_deriv_family (f : ordinal → ordinal) : deriv f = deriv_family (λ _ : unit, f)
rfl
theorem
ordinal.deriv_eq_deriv_family
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_zero (f) : deriv f 0 = nfp f 0
deriv_family_zero _
theorem
ordinal.deriv_zero
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_succ (f o) : deriv f (succ o) = nfp f (succ (deriv f o))
deriv_family_succ _ _
theorem
ordinal.deriv_succ
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_limit (f) {o} : is_limit o → deriv f o = bsup.{u 0} o (λ a _, deriv f a)
deriv_family_limit _
theorem
ordinal.deriv_limit
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_is_normal (f) : is_normal (deriv f)
deriv_family_is_normal _
theorem
ordinal.deriv_is_normal
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_id_of_nfp_id {f : ordinal → ordinal} (h : nfp f = id) : deriv f = id
((deriv_is_normal _).eq_iff_zero_and_succ is_normal.refl).2 (by simp [h])
theorem
ordinal.deriv_id_of_nfp_id
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.deriv_fp {f} (H : is_normal f) : ∀ o, f (deriv f o) = deriv f o
@deriv_family_fp unit (λ _, f) unit.star H
theorem
ordinal.is_normal.deriv_fp
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.le_iff_deriv {f} (H : is_normal f) {a} : f a ≤ a ↔ ∃ o, deriv f o = a
begin unfold deriv, rw ←le_iff_deriv_family (λ _ : unit, H), exact ⟨λ h _, h, λ h, h unit.star⟩ end
theorem
ordinal.is_normal.le_iff_deriv
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
is_normal.fp_iff_deriv {f} (H : is_normal f) {a} : f a = a ↔ ∃ o, deriv f o = a
by rw [←H.le_iff_eq, H.le_iff_deriv]
theorem
ordinal.is_normal.fp_iff_deriv
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_eq_enum_ord (H : is_normal f) : deriv f = enum_ord (function.fixed_points f)
by { convert deriv_family_eq_enum_ord (λ _ : unit, H), exact (set.Inter_const _).symm }
theorem
ordinal.deriv_eq_enum_ord
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "function.fixed_points", "set.Inter_const" ]
`ordinal.deriv` enumerates the fixed points of a normal function.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_eq_id_of_nfp_eq_id {f : ordinal → ordinal} (h : nfp f = id) : deriv f = id
(is_normal.eq_iff_zero_and_succ (deriv_is_normal _) is_normal.refl).2 $ by simp [h]
theorem
ordinal.deriv_eq_id_of_nfp_eq_id
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_add_zero (a) : nfp ((+) a) 0 = a * omega
begin simp_rw [←sup_iterate_eq_nfp, ←sup_mul_nat], congr, funext, induction n with n hn, { rw [nat.cast_zero, mul_zero, iterate_zero_apply] }, { nth_rewrite 1 nat.succ_eq_one_add, rw [nat.cast_add, nat.cast_one, mul_one_add, iterate_succ_apply', hn] } end
theorem
ordinal.nfp_add_zero
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "mul_one_add", "mul_zero", "nat.cast_add", "nat.cast_one", "nat.cast_zero", "nat.succ_eq_one_add" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_add_eq_mul_omega {a b} (hba : b ≤ a * omega) : nfp ((+) a) b = a * omega
begin apply le_antisymm (nfp_le_fp (add_is_normal a).monotone hba _), { rw ←nfp_add_zero, exact nfp_monotone (add_is_normal a).monotone (ordinal.zero_le b) }, { rw [←mul_one_add, one_add_omega] } end
theorem
ordinal.nfp_add_eq_mul_omega
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_eq_right_iff_mul_omega_le {a b : ordinal} : a + b = b ↔ a * omega ≤ b
begin refine ⟨λ h, _, λ h, _⟩, { rw [←nfp_add_zero a, ←deriv_zero], cases (add_is_normal a).fp_iff_deriv.1 h with c hc, rw ←hc, exact (deriv_is_normal _).monotone (ordinal.zero_le _) }, { have := ordinal.add_sub_cancel_of_le h, nth_rewrite 0 ←this, rwa [←add_assoc, ←mul_one_add, one_add_omega]...
theorem
ordinal.add_eq_right_iff_mul_omega_le
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone", "ordinal", "ordinal.add_sub_cancel_of_le", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_le_right_iff_mul_omega_le {a b : ordinal} : a + b ≤ b ↔ a * omega ≤ b
by { rw ←add_eq_right_iff_mul_omega_le, exact (add_is_normal a).le_iff_eq }
theorem
ordinal.add_le_right_iff_mul_omega_le
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_add_eq_mul_omega_add (a b : ordinal.{u}) : deriv ((+) a) b = a * omega + b
begin revert b, rw [←funext_iff, is_normal.eq_iff_zero_and_succ (deriv_is_normal _) (add_is_normal _)], refine ⟨_, λ a h, _⟩, { rw [deriv_zero, add_zero], exact nfp_add_zero a }, { rw [deriv_succ, h, add_succ], exact nfp_eq_self (add_eq_right_iff_mul_omega_le.2 ((le_add_right _ _).trans (le_succ _))) ...
theorem
ordinal.deriv_add_eq_mul_omega_add
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_mul_one {a : ordinal} (ha : 0 < a) : nfp ((*) a) 1 = a ^ omega
begin rw [←sup_iterate_eq_nfp, ←sup_opow_nat], { dsimp, congr, funext, induction n with n hn, { rw [nat.cast_zero, opow_zero, iterate_zero_apply] }, nth_rewrite 1 nat.succ_eq_one_add, rw [nat.cast_add, nat.cast_one, opow_add, opow_one, iterate_succ_apply', hn] }, { exact ha } end
theorem
ordinal.nfp_mul_one
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "nat.cast_add", "nat.cast_one", "nat.cast_zero", "nat.succ_eq_one_add", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_mul_zero (a : ordinal) : nfp ((*) a) 0 = 0
begin rw [←ordinal.le_zero, nfp_le_iff], intro n, induction n with n hn, { refl }, rwa [iterate_succ_apply, mul_zero] end
theorem
ordinal.nfp_mul_zero
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "mul_zero", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_zero_mul : nfp ((*) 0) = id
begin rw ←sup_iterate_eq_nfp, refine funext (λ a, (sup_le (λ n, _)).antisymm (le_sup (λ n, ((*) 0)^[n] a) 0)), induction n with n hn, { refl }, rw function.iterate_succ', change 0 * _ ≤ a, rw zero_mul, exact ordinal.zero_le a end
theorem
ordinal.nfp_zero_mul
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "function.iterate_succ'", "ordinal.zero_le", "sup_le", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_mul_zero : deriv ((*) 0) = id
deriv_eq_id_of_nfp_eq_id nfp_zero_mul
theorem
ordinal.deriv_mul_zero
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_mul_eq_opow_omega {a b : ordinal} (hb : 0 < b) (hba : b ≤ a ^ omega) : nfp ((*) a) b = a ^ omega.{u}
begin cases eq_zero_or_pos a with ha ha, { rw [ha, zero_opow omega_ne_zero] at *, rw [ordinal.le_zero.1 hba, nfp_zero_mul], refl }, apply le_antisymm, { apply nfp_le_fp (mul_is_normal ha).monotone hba, rw [←opow_one_add, one_add_omega] }, rw ←nfp_mul_one ha, exact nfp_monotone (mul_is_normal ha)...
theorem
ordinal.nfp_mul_eq_opow_omega
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
eq_zero_or_opow_omega_le_of_mul_eq_right {a b : ordinal} (hab : a * b = b) : b = 0 ∨ a ^ omega.{u} ≤ b
begin cases eq_zero_or_pos a with ha ha, { rw [ha, zero_opow omega_ne_zero], exact or.inr (ordinal.zero_le b) }, rw or_iff_not_imp_left, intro hb, change b ≠ 0 at hb, rw ←nfp_mul_one ha, rw ←one_le_iff_ne_zero at hb, exact nfp_le_fp (mul_is_normal ha).monotone hb (le_of_eq hab) end
theorem
ordinal.eq_zero_or_opow_omega_le_of_mul_eq_right
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone", "or_iff_not_imp_left", "ordinal", "ordinal.zero_le" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_eq_right_iff_opow_omega_dvd {a b : ordinal} : a * b = b ↔ a ^ omega ∣ b
begin cases eq_zero_or_pos a with ha ha, { rw [ha, zero_mul, zero_opow omega_ne_zero, zero_dvd_iff], exact eq_comm }, refine ⟨λ hab, _, λ h, _⟩, { rw dvd_iff_mod_eq_zero, rw [←div_add_mod b (a ^ omega), mul_add, ←mul_assoc, ←opow_one_add, one_add_omega, add_left_cancel] at hab, cases eq_zero_o...
theorem
ordinal.mul_eq_right_iff_opow_omega_dvd
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "not_lt_of_le", "ordinal", "zero_dvd_iff", "zero_mul" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
mul_le_right_iff_opow_omega_dvd {a b : ordinal} (ha : 0 < a) : a * b ≤ b ↔ a ^ omega ∣ b
by { rw ←mul_eq_right_iff_opow_omega_dvd, exact (mul_is_normal ha).le_iff_eq }
theorem
ordinal.mul_le_right_iff_opow_omega_dvd
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nfp_mul_opow_omega_add {a c : ordinal} (b) (ha : 0 < a) (hc : 0 < c) (hca : c ≤ a ^ omega) : nfp ((*) a) (a ^ omega * b + c) = a ^ omega.{u} * (succ b)
begin apply le_antisymm, { apply nfp_le_fp (mul_is_normal ha).monotone, { rw mul_succ, apply add_le_add_left hca }, { rw [←mul_assoc, ←opow_one_add, one_add_omega] } }, { cases mul_eq_right_iff_opow_omega_dvd.1 ((mul_is_normal ha).nfp_fp (a ^ omega * b + c)) with d hd, rw hd, apply mul...
theorem
ordinal.nfp_mul_opow_omega_add
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "monotone", "mul_le_mul_left'", "mul_lt_mul_iff_left", "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
deriv_mul_eq_opow_omega_mul {a : ordinal.{u}} (ha : 0 < a) (b) : deriv ((*) a) b = a ^ omega * b
begin revert b, rw [←funext_iff, is_normal.eq_iff_zero_and_succ (deriv_is_normal _) (mul_is_normal (opow_pos omega ha))], refine ⟨_, λ c h, _⟩, { rw [deriv_zero, nfp_mul_zero, mul_zero] }, { rw [deriv_succ, h], exact nfp_mul_opow_omega_add c ha zero_lt_one (one_le_iff_pos.2 (opow_pos _ ha)) }, end
theorem
ordinal.deriv_mul_eq_opow_omega_mul
set_theory.ordinal
src/set_theory/ordinal/fixed_point.lean
[ "set_theory.ordinal.arithmetic", "set_theory.ordinal.exponential" ]
[ "deriv", "mul_zero", "zero_lt_one" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_ordinal : Type*
ordinal
def
nat_ordinal
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
A type synonym for ordinals with natural addition and multiplication.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
ordinal.to_nat_ordinal : ordinal ≃o nat_ordinal
order_iso.refl _
def
ordinal.to_nat_ordinal
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal", "order_iso.refl", "ordinal" ]
The identity function between `ordinal` and `nat_ordinal`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_ordinal.to_ordinal : nat_ordinal ≃o ordinal
order_iso.refl _
def
nat_ordinal.to_ordinal
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal", "order_iso.refl", "ordinal" ]
The identity function between `nat_ordinal` and `ordinal`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_symm_eq : nat_ordinal.to_ordinal.symm = ordinal.to_nat_ordinal
rfl
theorem
nat_ordinal.to_ordinal_symm_eq
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal.to_nat_ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_to_nat_ordinal (a : nat_ordinal) : a.to_ordinal.to_nat_ordinal = a
rfl
theorem
nat_ordinal.to_ordinal_to_nat_ordinal
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_wf : @well_founded nat_ordinal (<)
ordinal.lt_wf
theorem
nat_ordinal.lt_wf
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal", "ordinal.lt_wf" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_zero : to_ordinal 0 = 0
rfl
theorem
nat_ordinal.to_ordinal_zero
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_one : to_ordinal 1 = 1
rfl
theorem
nat_ordinal.to_ordinal_one
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_eq_zero (a) : to_ordinal a = 0 ↔ a = 0
iff.rfl
theorem
nat_ordinal.to_ordinal_eq_zero
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_eq_one (a) : to_ordinal a = 1 ↔ a = 1
iff.rfl
theorem
nat_ordinal.to_ordinal_eq_one
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_max : (max a b).to_ordinal = max a.to_ordinal b.to_ordinal
rfl
theorem
nat_ordinal.to_ordinal_max
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_ordinal_min : (min a b).to_ordinal = min a.to_ordinal b.to_ordinal
rfl
theorem
nat_ordinal.to_ordinal_min
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
succ_def (a : nat_ordinal) : succ a = (a.to_ordinal + 1).to_nat_ordinal
rfl
theorem
nat_ordinal.succ_def
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
rec {β : nat_ordinal → Sort*} (h : Π a, β (to_nat_ordinal a)) : Π a, β a
λ a, h a.to_ordinal
def
nat_ordinal.rec
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal" ]
A recursor for `nat_ordinal`. Use as `induction x using nat_ordinal.rec`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
induction {p : nat_ordinal → Prop} : ∀ i (h : ∀ j, (∀ k, k < j → p k) → p j), p i
ordinal.induction
theorem
nat_ordinal.induction
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal", "ordinal.induction" ]
`ordinal.induction` but for `nat_ordinal`.
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_symm_eq : to_nat_ordinal.symm = nat_ordinal.to_ordinal
rfl
theorem
ordinal.to_nat_ordinal_symm_eq
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat_ordinal.to_ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_to_ordinal (a : ordinal) : a.to_nat_ordinal.to_ordinal = a
rfl
theorem
ordinal.to_nat_ordinal_to_ordinal
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_zero : to_nat_ordinal 0 = 0
rfl
theorem
ordinal.to_nat_ordinal_zero
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_one : to_nat_ordinal 1 = 1
rfl
theorem
ordinal.to_nat_ordinal_one
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_eq_zero (a) : to_nat_ordinal a = 0 ↔ a = 0
iff.rfl
theorem
ordinal.to_nat_ordinal_eq_zero
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_eq_one (a) : to_nat_ordinal a = 1 ↔ a = 1
iff.rfl
theorem
ordinal.to_nat_ordinal_eq_one
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_max (a b : ordinal) : to_nat_ordinal (max a b) = max a.to_nat_ordinal b.to_nat_ordinal
rfl
theorem
ordinal.to_nat_ordinal_max
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
to_nat_ordinal_min (a b : ordinal) : (linear_order.min a b).to_nat_ordinal = linear_order.min a.to_nat_ordinal b.to_nat_ordinal
rfl
theorem
ordinal.to_nat_ordinal_min
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd : ordinal → ordinal → ordinal
| a b := max (blsub.{u u} a $ λ a' h, nadd a' b) (blsub.{u u} b $ λ b' h, nadd a b') using_well_founded { dec_tac := `[solve_by_elim [psigma.lex.left, psigma.lex.right]] }
def
ordinal.nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
Natural addition on ordinals `a ♯ b`, also known as the Hessenberg sum, is recursively defined as the least ordinal greater than `a' ♯ b` and `a ♯ b'` for all `a' < a` and `b' < b`. In contrast to normal ordinal addition, it is commutative. Natural addition can equivalently be characterized as the ordinal resulting fr...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nmul : ordinal.{u} → ordinal.{u} → ordinal.{u}
| a b := Inf {c | ∀ (a' < a) (b' < b), nmul a' b ♯ nmul a b' < c ♯ nmul a' b'} using_well_founded { dec_tac := `[solve_by_elim [psigma.lex.left, psigma.lex.right]] }
def
ordinal.nmul
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
Natural multiplication on ordinals `a ⨳ b`, also known as the Hessenberg product, is recursively defined as the least ordinal such that `a ⨳ b + a' ⨳ b'` is greater than `a' ⨳ b + a ⨳ b'` for all `a' < a` and `b < b'`. In contrast to normal ordinal multiplication, it is commutative and distributive (over natural additi...
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_def (a b : ordinal) : a ♯ b = max (blsub.{u u} a $ λ a' h, a' ♯ b) (blsub.{u u} b $ λ b' h, a ♯ b')
by rw nadd
theorem
ordinal.nadd_def
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
lt_nadd_iff : a < b ♯ c ↔ (∃ b' < b, a ≤ b' ♯ c) ∨ ∃ c' < c, a ≤ b ♯ c'
by { rw nadd_def, simp [lt_blsub_iff] }
theorem
ordinal.lt_nadd_iff
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_le_iff : b ♯ c ≤ a ↔ (∀ b' < b, b' ♯ c < a) ∧ ∀ c' < c, b ♯ c' < a
by { rw nadd_def, simp [blsub_le_iff] }
theorem
ordinal.nadd_le_iff
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_lt_nadd_left (h : b < c) (a) : a ♯ b < a ♯ c
lt_nadd_iff.2 (or.inr ⟨b, h, le_rfl⟩)
theorem
ordinal.nadd_lt_nadd_left
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_lt_nadd_right (h : b < c) (a) : b ♯ a < c ♯ a
lt_nadd_iff.2 (or.inl ⟨b, h, le_rfl⟩)
theorem
ordinal.nadd_lt_nadd_right
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_le_nadd_left (h : b ≤ c) (a) : a ♯ b ≤ a ♯ c
begin rcases lt_or_eq_of_le h with h | rfl, { exact (nadd_lt_nadd_left h a).le }, { exact le_rfl } end
theorem
ordinal.nadd_le_nadd_left
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_le_nadd_right (h : b ≤ c) (a) : b ♯ a ≤ c ♯ a
begin rcases lt_or_eq_of_le h with h | rfl, { exact (nadd_lt_nadd_right h a).le }, { exact le_rfl } end
theorem
ordinal.nadd_le_nadd_right
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "le_rfl" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_comm : ∀ a b, a ♯ b = b ♯ a
| a b := begin rw [nadd_def, nadd_def, max_comm], congr; ext c hc; apply nadd_comm end using_well_founded { dec_tac := `[solve_by_elim [psigma.lex.left, psigma.lex.right]] }
theorem
ordinal.nadd_comm
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
blsub_nadd_of_mono {f : Π c < a ♯ b, ordinal.{max u v}} (hf : ∀ {i j} hi hj, i ≤ j → f i hi ≤ f j hj) : blsub _ f = max (blsub.{u v} a (λ a' ha', f (a' ♯ b) $ nadd_lt_nadd_right ha' b)) (blsub.{u v} b (λ b' hb', f (a ♯ b') $ nadd_lt_nadd_left hb' a))
begin apply (blsub_le_iff.2 (λ i h, _)).antisymm (max_le _ _), { rcases lt_nadd_iff.1 h with ⟨a', ha', hi⟩ | ⟨b', hb', hi⟩, { exact lt_max_of_lt_left ((hf h (nadd_lt_nadd_right ha' b) hi).trans_lt (lt_blsub _ _ _)) }, { exact lt_max_of_lt_right ((hf h (nadd_lt_nadd_left hb' a) hi).trans_lt (lt_blsub _ _ _))...
theorem
ordinal.blsub_nadd_of_mono
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "lt_max_of_lt_left", "lt_max_of_lt_right" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_assoc : ∀ a b c, a ♯ b ♯ c = a ♯ (b ♯ c)
| a b c := begin rw [nadd_def a (b ♯ c), nadd_def, blsub_nadd_of_mono, blsub_nadd_of_mono, max_assoc], { congr; ext d hd; apply nadd_assoc }, { exact λ i j _ _ h, nadd_le_nadd_left h a }, { exact λ i j _ _ h, nadd_le_nadd_right h c } end using_well_founded { dec_tac := `[solve_by_elim [psigma.lex.left, psig...
theorem
ordinal.nadd_assoc
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_zero : a ♯ 0 = a
begin induction a using ordinal.induction with a IH, rw [nadd_def, blsub_zero, max_zero_right], convert blsub_id a, ext b hb, exact IH _ hb end
theorem
ordinal.nadd_zero
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "ordinal.induction" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
zero_nadd : 0 ♯ a = a
by rw [nadd_comm, nadd_zero]
theorem
ordinal.zero_nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_one : a ♯ 1 = succ a
begin induction a using ordinal.induction with a IH, rw [nadd_def, blsub_one, nadd_zero, max_eq_right_iff, blsub_le_iff], intros i hi, rwa [IH i hi, succ_lt_succ_iff] end
theorem
ordinal.nadd_one
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "max_eq_right_iff", "ordinal.induction" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
one_nadd : 1 ♯ a = succ a
by rw [nadd_comm, nadd_one]
theorem
ordinal.one_nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_succ : a ♯ succ b = succ (a ♯ b)
by rw [←nadd_one (a ♯ b), nadd_assoc, nadd_one]
theorem
ordinal.nadd_succ
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
succ_nadd : succ a ♯ b = succ (a ♯ b)
by rw [←one_nadd (a ♯ b), ←nadd_assoc, one_nadd]
theorem
ordinal.succ_nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nadd_nat (n : ℕ) : a ♯ n = a + n
begin induction n with n hn, { simp }, { rw [nat.cast_succ, add_one_eq_succ, nadd_succ, add_succ, hn] } end
theorem
ordinal.nadd_nat
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "nat.cast_succ" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
nat_nadd (n : ℕ) : ↑n ♯ a = a + n
by rw [nadd_comm, nadd_nat]
theorem
ordinal.nat_nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_le_nadd : a + b ≤ a ♯ b
begin apply b.limit_rec_on, { simp }, { intros c h, rwa [add_succ, nadd_succ, succ_le_succ_iff] }, { intros c hc H, rw [←is_normal.blsub_eq.{u u} (add_is_normal a) hc, blsub_le_iff], exact λ i hi, (H i hi).trans_lt (nadd_lt_nadd_left hi a) } end
theorem
ordinal.add_le_nadd
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_covariant_class_lt : covariant_class nat_ordinal.{u} nat_ordinal.{u} (+) (<)
⟨λ a b c h, nadd_lt_nadd_left h a⟩
instance
nat_ordinal.add_covariant_class_lt
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "covariant_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_covariant_class_le : covariant_class nat_ordinal.{u} nat_ordinal.{u} (+) (≤)
⟨λ a b c h, nadd_le_nadd_left h a⟩
instance
nat_ordinal.add_covariant_class_le
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "covariant_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83
add_contravariant_class_le : contravariant_class nat_ordinal.{u} nat_ordinal.{u} (+) (≤)
⟨λ a b c h, by { by_contra' h', exact h.not_lt (add_lt_add_left h' a) }⟩
instance
nat_ordinal.add_contravariant_class_le
set_theory.ordinal
src/set_theory/ordinal/natural_ops.lean
[ "set_theory.ordinal.arithmetic", "tactic.abel" ]
[ "contravariant_class" ]
https://github.com/leanprover-community/mathlib
65a1391a0106c9204fe45bc73a039f056558cb83