fact: Definition EPpermi_next ph n (s:= EPperm_rec n) (h := fun i => Vf g (Vf ph (Vf s i))) (k := (EPperm_next_index n s)) := Yo (n = \0c) \0c (EPpermi_fct h n k).
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat)