fact: Definition totally {I : choiceType} : set_system {fset I} := filter_from setT (fun A => [set B | A `<=` B]).
imports: HB(structures) mathcomp(all_ssreflect ssralg ssrint ssrnum finmap matrix) mathcomp(interval zmodp) mathcomp(boolp classical_sets) ereal reals Rstruct signed topology normedtype