proposition: Lemma set1_neq0 A (a : A) : [set a] != set0.
proof: Proof. by apply/set0P; exists a. 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