proposition: Fact lex1 (x : T * T') : x <= (top, top).
proof: Proof. by rewrite /<=%O /= /le !lex1. Qed.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat choice seq) mathcomp(path fintype tuple bigop finset div prime finfun) mathcomp(finset)