Let x and y be given.
Let a be given.
Let i be given.
Assume Hiconj.
We prove the intermediate
claim HiO:
i ∈ ω.
We prove the intermediate
claim HxiR:
apply_fun x i ∈ R.
We prove the intermediate
claim HyiR:
apply_fun y i ∈ R.
We prove the intermediate
claim HSi:
ordsucc i ∈ ω.
An
exact proof term for the current goal is
(omega_ordsucc i HiO).
rewrite the current goal using Hai (from left to right).
An exact proof term for the current goal is HmulR.
∎