rddl_block : rddl_block domain_block
                      | rddl_block instance_block
                      | rddl_block nonfluent_block
                      | empty

def p_rddl_block(self, p):
        '''rddl_block : rddl_block domain_block
                      | rddl_block instance_block
                      | rddl_block nonfluent_block
                      | empty'''
        if p[1] is None:
            p[0] = dict()
        else:
            name, block = p[2]
            p[1][name] = block
            p[0] = p[1]