proposition: Lemma add_row_mult_nontarget_row {m n} (r1 r2 : ⟦ m ⟧%stn) (s : R) (mat : Matrix R m n) : ∏ (i : ⟦ m ⟧%stn), r2 ≠ i -> add_row_mult r1 r2 s mat i = mat i.
proof: Proof. intros i r2_ne_i. unfold add_row_mult. now rewrite (stn_eq_or_neq_right (issymm_stnneq r2_ne_i)). Defined.
imports: UniMath.Foundations.All UniMath.MoreFoundations.All UniMath.Combinatorics.StandardFiniteSets UniMath.Combinatorics.Vectors UniMath.Algebra.Matrix UniMath.Algebra.RigsAndRings UniMath.Algebra.IteratedBinaryOperations UniMath.Algebra.Domains_and_Fields UniMath.Algebra.GaussianElimination.Auxiliary UniMath.Algebra.GaussianElimination.Vectors UniMath.Algebra.GaussianElimination.Matrices