fact: Structure proper_addv_expr := ProperSumvExpr { proper_addv_val :> {vspace vT}; proper_addv_dim :> nat; _ : mxsum_spec (vs2mx proper_addv_val) proper_addv_dim }.
imports: HB(structures) mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat seq choice) mathcomp(fintype bigop finfun tuple) mathcomp(ssralg matrix mxalgebra zmodp)