proposition: Lemma ltBSide x y (b b' : bool) : BSide b x < BSide b' y = (x < y ?<= if b && ~~ b').
proof: Proof. by []. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(div fintype bigop order ssralg finset fingroup) mathcomp(ssrnum)