fact: Definition is_convex_set_n (X : set T) : bool := `[< forall n (g : 'I_n -> T) (d : {fdist 'I_n}), g @` setT `<=` X -> X (<|>_d g) >].
imports: HB(structures) mathcomp(all_ssreflect ssralg fingroup perm matrix) mathcomp(mathcomp_extra boolp classical_sets Rstruct) mathcomp(ssrnum ereal) mathcomp(lra Rstruct reals) Reals ssrR Reals_ext Ranalysis_ext ssr_ext ssralg_ext logb realType_ext fdist