proposition: Lemma line_scale_row_neq n m k l a (M: 'M[R]_(n,m)): k != l -> row l (line_scale k a M) = row l M.
proof: Proof. move/negbTE => hkl. by apply/rowP => i; rewrite !mxE eq_sym hkl mul1r. Qed.
imports: mathcomp(ssreflect ssrfun ssrbool eqtype ssrnat div seq) mathcomp(ssralg fintype perm choice) mathcomp(matrix bigop zmodp mxalgebra poly mxpoly)