def __init__(self, agent):
        if agent:
            self.state = PddlStateSmlAdapter(self, agent)
        else:
            self.state = PddlState()

        self.state.predicates['on__table'] = set()
        self.state.predicates['on'] = set()
        self.state.predicates['clear'] = set()
        self.pred_param_names = {}

        self.pred_param_names['on__table'] = ('x', )

        self.pred_param_names['on'] = (
            'x',
            'y',
        )

        self.pred_param_names['clear'] = ('x', )