fact: Definition add_row_mult_target_row {m n} (r1 r2 : ⟦ m ⟧%stn) (s : R) (mat : Matrix R m n) (c : ⟦ n ⟧%stn) : (add_row_mult r1 r2 s mat) r2 c = (mat r2 c + s * mat r1 c)%rig.
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