Apply FalseE to the current goal.
Apply HF0ne to the current goal.
Let f be given.
We prove the intermediate
claim Hcod:
f ∈ (F0 ∪ (T ∪ {y})).
An
exact proof term for the current goal is
(binunionI1 F0 (T ∪ {y}) f HfF0).
We prove the intermediate
claim Hbij0Ty:
bijection 0 (F0 ∪ (T ∪ {y})) eT.
rewrite the current goal using Hn0 (from right to left).
An exact proof term for the current goal is HbijTy.
We prove the intermediate
claim Hexk:
∃k : set, k ∈ 0 ∧ apply_fun eT k = f.
An
exact proof term for the current goal is
(bijection_surj 0 (F0 ∪ (T ∪ {y})) eT f Hbij0Ty Hcod).
Apply Hexk to the current goal.
Let k be given.
Assume Hkpack.
Apply Hexm to the current goal.
Let m be given.
We prove the intermediate
claim HmNat:
nat_p m.
We prove the intermediate
claim HnTEq:
nT = ordsucc m.
We prove the intermediate
claim HmO:
m ∈ ω.
An
exact proof term for the current goal is
(nat_p_omega m HmNat).
We prove the intermediate
claim HyInCod:
y ∈ (F0 ∪ (T ∪ {y})).
Let f be given.
An exact proof term for the current goal is (HvalUI0 f HfF0).
We prove the intermediate
claim Hfx0:
apply_fun f x = 0.
An exact proof term for the current goal is (HzeroTy f HfT).
rewrite the current goal using Hfx0 (from left to right).
rewrite the current goal using HnTEq (from right to left).
An exact proof term for the current goal is HbijTy.
Apply Hdrop to the current goal.
Let e' be given.
Assume He'pack.
We prove the intermediate
claim HbijDrop:
bijection m ((F0 ∪ (T ∪ {y})) ∖ {y}) e'.
We prove the intermediate
claim HeqSet:
((F0 ∪ (T ∪ {y})) ∖ {y}) = (F0 ∪ T).
Let u be given.
We prove the intermediate
claim HuU:
u ∈ (F0 ∪ (T ∪ {y})).
An
exact proof term for the current goal is
(setminusE1 (F0 ∪ (T ∪ {y})) {y} u Hu).
We prove the intermediate
claim HuNy:
u ∉ {y}.
An
exact proof term for the current goal is
(setminusE2 (F0 ∪ (T ∪ {y})) {y} u Hu).
An
exact proof term for the current goal is
(binunionI1 F0 T u HuF0).
An
exact proof term for the current goal is
(binunionI2 F0 T u HuT).
Apply FalseE to the current goal.
An exact proof term for the current goal is (HuNy Huy).
Let u be given.
Apply (binunionE F0 T u Hu) to the current goal.
We prove the intermediate
claim HuU:
u ∈ (F0 ∪ (T ∪ {y})).
An
exact proof term for the current goal is
(binunionI1 F0 (T ∪ {y}) u HuF0).
We prove the intermediate
claim HuNy:
u ∉ {y}.
We prove the intermediate
claim Hueq:
u = y.
An
exact proof term for the current goal is
(SingE y u Huy).
Apply HyNotF0 to the current goal.
rewrite the current goal using Hueq (from right to left).
An exact proof term for the current goal is HuF0.
An
exact proof term for the current goal is
(setminusI (F0 ∪ (T ∪ {y})) {y} u HuU HuNy).
We prove the intermediate
claim HuU:
u ∈ (F0 ∪ (T ∪ {y})).
We prove the intermediate
claim HuNy:
u ∉ {y}.
We prove the intermediate
claim Hueq:
u = y.
An
exact proof term for the current goal is
(SingE y u Huy).
Apply HyNot to the current goal.
rewrite the current goal using Hueq (from right to left).
An exact proof term for the current goal is HuT.
An
exact proof term for the current goal is
(setminusI (F0 ∪ (T ∪ {y})) {y} u HuU HuNy).
We prove the intermediate
claim HbijDrop2:
bijection m (F0 ∪ T) e'.
rewrite the current goal using HeqSet (from right to left).
An exact proof term for the current goal is HbijDrop.
We prove the intermediate
claim HTfin2:
finite T.
An exact proof term for the current goal is HTfin.
We prove the intermediate
claim HnotF0T2:
∀f : set, f ∈ T → ¬ (f ∈ F0).
Let f be given.
An
exact proof term for the current goal is
(HnotF0Ty f (binunionI1 T {y} f HfT)).
We prove the intermediate
claim HzeroT2:
∀f : set, f ∈ T → apply_fun f x = 0.
Let f be given.
An
exact proof term for the current goal is
(HzeroTy f (binunionI1 T {y} f HfT)).
We prove the intermediate
claim HmO2:
m ∈ ω.
An
exact proof term for the current goal is
(nat_p_omega m HmNat).
An exact proof term for the current goal is (IH m e' HTfin2 HnotF0T2 HzeroT2 HmO2 HbijDrop2).
rewrite the current goal using HnTEq (from left to right) at position 1.
rewrite the current goal using HsumDrop (from left to right) at position 1.
An exact proof term for the current goal is Hind.