public AbstractExpression LExpr(ProcedureBuilder pb) throws Exception {
        Token l_token;
        AbstractExpression RetValue = Expression(pb);
        while (Current_Token == Token.TOK_GT
                || Current_Token == Token.TOK_LT
                || Current_Token == Token.TOK_GTE
                || Current_Token == Token.TOK_LTE
                || Current_Token == Token.TOK_NEQ
                || Current_Token == Token.TOK_EQ) {
            l_token = Current_Token;
            Current_Token = GetNext();
            AbstractExpression e2 = Expression(pb);
            RelationalOperators relop = GetRelationalOperator(l_token);
            RetValue = new RelationalExpression(relop, RetValue, e2);
        }
        return RetValue;

    }