state_invariant_section : STATE_INVARIANTS LCURLY state_invariant_list RCURLY SEMI
                                   | STATE_INVARIANTS LCURLY RCURLY SEMI

def p_state_invariant_section(self, p):
        '''state_invariant_section : STATE_INVARIANTS LCURLY state_invariant_list RCURLY SEMI
                                   | STATE_INVARIANTS LCURLY RCURLY SEMI'''
        if len(p) == 6:
            p[0] = ('invariants', p[3])
        elif len(p) == 5:
            p[0] = ('invariants', [])
        self._print_verbose('invariants')