horizon_spec_section : HORIZON ASSIGN_EQUAL pos_int_type_or_pos_inf SEMI
                                | HORIZON ASSIGN_EQUAL TERMINATE_WHEN LPAREN expr RPAREN

def p_horizon_spec_section(self, p):
        '''horizon_spec_section : HORIZON ASSIGN_EQUAL pos_int_type_or_pos_inf SEMI
                                | HORIZON ASSIGN_EQUAL TERMINATE_WHEN LPAREN expr RPAREN'''
        if len(p) == 5:
            p[0] = ('horizon', p[3])
        elif len(p) == 7:
            p[0] = ('horizon', p[5])
        self._print_verbose('horizon')