using System;

using org.matheval;

public class Program

{

    public static void Main()

    {

        Expression expr = new Expression("SIN(PI())^2+COS(PI())^2");

        Object value = expr.Eval(); //return 1      

        Console.WriteLine("SIN(PI())^2+COS(PI())^2= "+value);

        expr = new Expression("sin(a) - cos(a) = SQRT(2) * sin(a - pi / 4)");

        value = expr.Bind("a", Math.PI/5).Eval<bool>(); //return true

        Console.WriteLine("sin(PI/5) - cos(PI/5) = SQRT(2) * sin(PI/5 - pi / 4) => "+value);

        expr = new Expression("tan(a)^3-((3*sin(a)-sin(3*a))/(3*cos(a)+cos(3*a)))");

        value = expr.Bind("a", Math.PI/6).Eval<Decimal>(); //return 0   

        Console.WriteLine("tan(PI/6)^3-((3*sin(PI/6)-sin(3*PI/6))/(3*cos(PI/6)+cos(3*PI/6))) = "+value);

    }

}