proposition: Lemma lubUK (y x : L) : (x [+] y) [+] y = x [+] y.
proof: Proof. by rewrite -lubA lubxx. 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