fact: Definition back_sub_stmt { n : nat } {F : fld} (mat : Matrix F n n) (vec : Vector F n) (ut : @is_upper_triangular F _ _ mat) (df : @diagonal_all_nonzero F _ mat) := ∑ v : (Vector F n), (@matrix_mult F _ _ mat _ (col_vec v)) = (col_vec vec).
imports: UniMath.MoreFoundations.PartA UniMath.MoreFoundations.Nat UniMath.MoreFoundations.Tactics UniMath.Algebra.Matrix UniMath.Algebra.Domains_and_Fields UniMath.Algebra.Matrix UniMath.Algebra.RigsAndRings UniMath.Algebra.IteratedBinaryOperations UniMath.Algebra.GaussianElimination.Auxiliary UniMath.Algebra.GaussianElimination.Vectors UniMath.Algebra.GaussianElimination.Matrices UniMath.Algebra.GaussianElimination.Elimination