fact: Definition mxOver_pred (S : {pred T}) := fun M : 'M[T]_(m, n) => [forall i, [forall j, M i j \in S]].
imports: HB(structures) mathcomp(ssreflect ssrbool ssrfun eqtype ssrnat seq choice) mathcomp(fintype finfun bigop finset fingroup perm order) mathcomp(div prime binomial ssralg countalg finalg zmodp)