proposition: Lemma vecsum_eq_zero {n} (v : Vector R n) (v_0 : v ~ const_vec 0%rig) : Σ v = 0%rig.
proof: Proof. etrans. { apply vecsum_eq, v_0. } apply vecsum_zero. Defined.
imports: UniMath.Foundations.PartA UniMath.Foundations.NaturalNumbers UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Nat UniMath.MoreFoundations.Tactics UniMath.Combinatorics.StandardFiniteSets UniMath.Combinatorics.Vectors UniMath.Algebra.RigsAndRings UniMath.Algebra.IteratedBinaryOperations UniMath.Algebra.Matrix UniMath.Algebra.GaussianElimination.Auxiliary