private Instance NewMathType()
{
// math nao tem prototype
var math = new Instance();
math.SetField("PI", new Instance(Math.PI));
math.SetMethod("sqrt", (s, a) => new Instance(Math.Sqrt((double)a[0].Scalar)));
math.SetMethod("cos", (s, a) => new Instance(Math.Cos((double)a[0].Scalar)));
math.SetMethod("sin", (s, a) => new Instance(Math.Sin((double)a[0].Scalar)));
math.SetMethod("abs", (s, a) => new Instance(Math.Abs((double)a[0].Scalar)));
math.SetMethod("round", (s, a) => new Instance(Math.Round((double)a[0].Scalar)));
math.SetMethod("max", (s, a) => new Instance(Math.Max(a[0].Scalar, a[1].Scalar)));
return math;
}