proposition: Lemma lubCA : left_commutative lub.
proof: Proof. by move=> x y z; rewrite !lubA [X in X [+] _]lubC. Qed.
imports: HB(structures) Reals mathcomp(all_ssreflect ssralg ssrnum) mathcomp(mathcomp_extra boolp classical_sets Rstruct reals) mathcomp(finmap) Reals_ext realType_ext classical_sets_ext ssrR fdist fsdist convex