Let X be given.
Assume Hfin.
Apply Hfin to the current goal.
Let n be given.
We prove the intermediate
claim Hn:
n ∈ ω.
An
exact proof term for the current goal is
(andEL (n ∈ ω) (equip X n) Hpair).
We prove the intermediate
claim Heq:
equip X n.
An
exact proof term for the current goal is
(andER (n ∈ ω) (equip X n) Hpair).
We prove the intermediate
claim Hn_sub:
n ⊆ ω.
We prove the intermediate
claim Hcount_n:
atleastp n ω.
An
exact proof term for the current goal is
(Subq_atleastp n ω Hn_sub).
We prove the intermediate
claim Hcount_X:
atleastp X n.
An
exact proof term for the current goal is
(atleastp_tra X n ω Hcount_X Hcount_n).
∎