proposition: Lemma eqrXn2 n x y : (0 < n)%N -> 0 <= x -> 0 <= y -> (x ^+ n == y ^+ n) = (x == y).
proof: Proof. by move=> ngt0 xge0 yge0; rewrite (inj_in_eq (pexpIrn _)). Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(ssrAC div fintype path bigop order finset fingroup) mathcomp(ssralg poly)