Weak Cost Register Automata are Still Powerful [article]

Shaull Almagor, Michaël Cadilhac, Filip Mazowiecki, Guillermo A. Pérez
2018 arXiv   pre-print
We consider one of the weakest variants of cost register automata over a tropical semiring, namely copyless cost register automata over N with updates using and increments. We show that this model can simulate, in some sense, the runs of counter machines with zero-tests. We deduce that a number of problems pertaining to that model are undecidable, in particular equivalence, disproving a conjecture of Alur et al. from 2012. To emphasize how weak these machines are, we also show that they can be
more » ... xpressed as a restricted form of linearly-ambiguous weighted automata.
arXiv:1804.06336v1 fatcat:kuxxb6cokbgllitrwm6acbwham