Метод простых итераций для СЛАУ

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace МПИ_СЛАУ
{
    class Program
    {
        delegate double func(double[] x);
        static void Main(string[] args)
        {
              const double eps = 0.00001;

              func x1 = (x) =>  0 *x[0] - 2.42 / 40.41  *  x[1] -3.86/40.41 * x[2] + 20.41/40.41;
              func x2 = (x) => -2.31/21.49 * x[0] + 0 * x[1] - 4.55/21.49 * x[2] + 30.11/21.49;
              func x3 = (x) => -2.49 / 25.69 * x[0] - 4.85 / 25.96 * x[1] + 0 * x[2] + 12.24/25.96;

              double norma = 0.31;

              var xn = new double[3] { 0.51, 1.4,0.47};
              var f = new double[3] { x1(xn), x2(xn), x3(xn) };

              while (norma /(1-norma) *  f.Diff(xn).Abs().Max()  > eps)
              {
                  xn = new double[3] { x1(xn), x2(xn), x3(xn) };
                  f = new double[3] { x1(xn), x2(xn), x3(xn) };
              }

            Console.WriteLine("{0}    {1}    {2}", f[0], f[1], f[2]);

        }



    }
    public static class MyExtension
    {
        public static double[] Diff(this double[] a, double[] b)
        {
            if (a.Length == 3 && b.Length == 3)
                return new double[] { a[0] - b[0], a[1] - b[1], a[2] - b[2] };
            else throw new ArgumentOutOfRangeException();
        }

        public static double[] Abs(this double[] a)
        {
            for (int i = 0; i < a.Length; ++i) a[i] *= a[i] > 0 ? 1 : -1;
            return a;
        }

    }
}