Flattening and simulation of asynchronous divisionless P systems with active membranes

We prove that asynchronous P systems with active membranes without division rules can be simulated by single-membrane transition P systems using cooperative rules, even if the synchronisation mechanisms provided by electrical charges and membrane dissolution are exploited. In turn, the latter systems can be simulated by means of place/transition Petri nets, and hence all these models are computationally weaker than Turing machines