On Trace Languages Generated by Spiking Neural P Systems

We extend to spiking neural P systems a notion investigated in the "stan- dard" membrane systems: the language of the traces of a distinguished object. In our case, we distinguish a spike by "marking" it and we follow its path through the neurons of the system, thus obtaining a language. Several examples are discussed and some preliminary results about this way of associating a language with a spiking neural P system are given, together with a series of topics for further research. For instance, we show that each regular language is the morphic image of a trace language intersected with a very particular regular language, while each recursively enumerable language over the one-letter alphabet is the projection of a trace language.