proposition: Lemma matlunax2 : ∏ (m n: nat) (mat : Matrix R n m), (identity_matrix ** mat) = mat.
proof: Proof. intros. apply funextfun. intros i. apply funextfun. intros j. unfold matrix_mult, row. use sum_id_pointwise_prod. Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.StandardFiniteSets UniMath.Combinatorics.Vectors UniMath.Algebra.RigsAndRings UniMath.Algebra.IteratedBinaryOperations UniMath.Algebra.Matrix UniMath.Algebra.Domains_and_Fields UniMath.Algebra.GaussianElimination.Auxiliary UniMath.Algebra.GaussianElimination.Vectors