fact: Definition head_hpoly (p : hpoly A) := match p with | Pc a => a | PX a n p' => a end.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq zmodp) mathcomp(path choice fintype tuple finset ssralg bigop poly polydiv) CoqEAL(param refinements pos hrel poly_op)