fact: Fixpoint limit_fct x := if x is cons a n b then if (b==zero) then if(a==zero) then phi3 a else if (T1is_succ a) then if (n==0) then phi3 (T1pred a) else phi1 (cons a n.-1 zero) (phi3 (T1pred a)) else if(n==0) then (phi2 (limit_fct a)) else phi1 (cons a n.-1 zero) (phi2 (limit_fct a)) else phi1 (cons a n zero) (limit_fct b) else phi3 zero.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(fintype bigop)