Let f, g, h and n be given.
We prove the intermediate
claim HfnR:
apply_fun f n ∈ R.
We prove the intermediate
claim HgnR:
apply_fun g n ∈ R.
We prove the intermediate
claim HhnR:
apply_fun h n ∈ R.
rewrite the current goal using HdefL (from left to right).
rewrite the current goal using HdefR1 (from left to right).
rewrite the current goal using HdefR2 (from left to right).
An
exact proof term for the current goal is
(abs_SNo_triangle a b c HfnS HgnS HhnS).
∎