gistfile1.txt

static String simplify(String expression)
{
    expression = expression.trim();
    while (expression.contains('('))
    {
         string parentLogic = expression.substringAfter('(').substringBeforeLast(')');

	      string result = evaluate(parentLogic) ? 'true' : 'false';

	      expression = expression.replace('(' + parentLogic + ')', result);
    }
    return expression;
}
static Boolean evaluate(String expression)
{
    expression = simplify(expression);
    if (!isSimpleExpression(expression))
    {
        if (expression.contains('&&'))
        {
            return andJoin(
                expression.substringBefore('&&'),
                expression.substringAfter('&&')
            );
        }
        if (expression.contains('||'))
        {
            return orJoin(
                expression.substringBefore('||'),
                expression.substringAfter('||')
            );
        }
        if (expression.startsWith('!')) return !evaluate(expression.substring(1));
    }
    return Boolean.valueOf(expression);
}