proposition: Lemma Sba_mK: cancel Sba_m Sba_p.
proof: Proof. by move => x; rewrite /Sba_m /Sba_p addrCA subrr addr0. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat) mathcomp(seq choice fintype order bigop ssralg) mathcomp(div ssrnum ssrint rat prime path binomial) mathcomp(tuple finset) gaia(fibm)