using System;

using org.matheval;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        Expression expression = new Expression("SUM(1,2,3) + true");

        //validate expression

        List<String> errors = expression.GetError(); 

        if(errors.Count > 0)

        {

          foreach(String error in errors)

          {

            Console.WriteLine(error);

          }

        }       

    }

}