p[0] = Rest()
        if len(p) > 2:
            p[0].duration = p[2]

    def node(p):
        '''node: NODE
        '''
        p[0] = tree.tree(node.strip("(").strip(")"))
        p[0] = tree.Tree(node.strip("(").strip(")"))


    def p_error(p):
        raise Exception("Syntax error at '%s' of element type %s" % (p.value, p.type))
        
    yacc.yacc()