FilterExpr : FilterExpr Predicate

def p_filter_expr_predicate(p):
    """
    FilterExpr : FilterExpr Predicate
    """
    if not hasattr(p[1], 'append_predicate'):
        p[1] = ast.PredicatedExpression(p[1])
    p[1].append_predicate(p[2])
    p[0] = p[1]