We use
0 to
witness the existential quantifier.
We use k to witness the existential quantifier.
We use
1 to
witness the existential quantifier.
We use n to witness the existential quantifier.
We prove the intermediate
claim Heq0k:
(0,k) = (0,k).
We prove the intermediate
claim Heq1n:
(1,n) = (1,n).
We prove the intermediate
claim H12:
0 ∈ 2 ∧ k ∈ ω.
An
exact proof term for the current goal is
(andI (0 ∈ 2) (k ∈ ω) In_0_2 HkOmega).
We prove the intermediate
claim H123:
(0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2.
We prove the intermediate
claim H1234:
((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) ∧ n ∈ ω.
An
exact proof term for the current goal is
(andI ((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) (n ∈ ω) H123 HnOmega).
We prove the intermediate
claim H12345:
(((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) ∧ n ∈ ω) ∧ (0,k) = (0,k).
An
exact proof term for the current goal is
(andI (((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) ∧ n ∈ ω) ((0,k) = (0,k)) H1234 Heq0k).
We prove the intermediate
claim H123456:
((((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) ∧ n ∈ ω) ∧ (0,k) = (0,k)) ∧ (1,n) = (1,n).
An
exact proof term for the current goal is
(andI ((((0 ∈ 2 ∧ k ∈ ω) ∧ 1 ∈ 2) ∧ n ∈ ω) ∧ (0,k) = (0,k)) ((1,n) = (1,n)) H12345 Heq1n).
We prove the intermediate
claim Hlex:
0 ∈ 1 ∨ (0 = 1 ∧ k ∈ n).
Apply andI to the current goal.
An exact proof term for the current goal is H123456.
An exact proof term for the current goal is Hlex.
∎