fact: Definition join1 : L' -> L := fun X => NECSet.Pack (NECSet.Class (CSet.Mixin (hull_is_convex _)) (NESet.Mixin (join1'_neq0 X))).
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