fact: Definition conform_mx m' n' B A := match m =P m', n =P n' with | ReflectT eq_m, ReflectT eq_n => castmx (eq_m, eq_n) A | _, _ => B end.
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)