public static readonly double Epsilon = Math.Pow(2d, -52d);

        public static bool IsEqualTo(this double value, double other) { return IsEqualTo(value, other, Epsilon); }

        public static bool IsEqualTo(this double value, double other, double absEps)
        {
            var specialCase = CheckSpecialCases(value, other);
            if (specialCase.HasValue) return specialCase.Value;
            if (value ≥ .0)
            {
                if (other ≥ .0)
                    return value > other
                        ? (value - other) / value < Epsilon
                        : (other - value) / other < Epsilon;
            }
            else if (other < .0)
                return value > other
                    ? (other - value) / other < Epsilon
                    : (value - other) / value < Epsilon;
            return Math.Abs(value - other) < absEps;
        }

        private static bool? CheckSpecialCases(double value, double other)
        {
            if (value == other) return true;
            if (double.IsNaN(value)) return double.IsNaN(other);
            if (double.IsNegativeInfinity(value)) return double.IsNegativeInfinity(other);
            if (double.IsPositiveInfinity(value)) return double.IsPositiveInfinity(other);
            if (double.IsNaN(other) || double.IsInfinity(other)) return false;
            return null;
        }

double d1 = 0.1f;
double d2 = 0.001f;
double d3 = 1 - d1*10;
double d4 = 1 - d2*1000;
Console.WriteLine (d3);
Console.WriteLine (d4);