proposition: Lemma map2_row_mx : map2_mx (row_mx Aul Aur) (row_mx A'ul A'ur) = row_mx (map2_mx Aul A'ul) (map2_mx Aur A'ur).
proof: Proof. by apply/matrixP=> i j; do 2![rewrite !mxE //; case: split => ?]. Qed.
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)