fact: Definition counting (T : choiceType) (R : realType) (X : set T) : \bar R := if `[< finite_set X >] then (#|` fset_set X |)%:R%:E else +oo.
imports: mathcomp(all_ssreflect all_algebra finmap) mathcomp(mathcomp_extra boolp classical_sets functions) mathcomp(cardinality fsbigop ) reals ereal signed topology normedtype sequences esum numfun HB(structures)