fact: Variable (F : functor) (ret : idfun ~> F) (join : F \o F ~> F).
imports: ssrmatching Reals JMeq mathcomp(all_ssreflect ssralg ssrnum) mathcomp(mathcomp_extra Rstruct reals) infotheo(Reals_ext) infotheo(realType_ext) monae_lib HB(structures)