fact: Fixpoint bigpoly (x : int) (n : nat) : {poly int} := match n with | 0 => x%:P | n.+1 => x%:P + (bigpoly (x+1) n) * 'X end.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq ssralg) mathcomp(path choice fintype tuple finset bigop poly polydiv) CoqEAL(hrel param refinements poly_op) mathcomp(ssrint) CoqEAL(binnat binint seqpoly)