fact: Definition subid m n (I : 'cV[R]_m) (J : 'cV[R]_n) : bool := [forall i, member (I i 0) J].
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq path) mathcomp(ssralg fintype perm choice fingroup) mathcomp(matrix bigop zmodp mxalgebra poly) ssrcomplements