fact: Definition falling_rec (p : Z) (a : Z) (n : nat) : Z := (a * (p - (Z.of_nat n) + 1))%Z.
imports: Coq(ZArith Rfunctions NaryFunctions Lia) mathcomp.ssreflect(ssreflect ssrbool ssrfun eqtype ssrnat seq fintype bigop tuple) MathComp