proposition: Fact addqC : commutative addq.
proof: Proof. by move=> x y; rewrite !addq_def /= addq_subdefC. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop order ssralg countalg div ssrnum) mathcomp(ssrint prime archimedean)