Cut-elimination and the decidability of reachability in alternating pushdown systems
arXiv:1410.8470
Abstract
We give a new proof of the decidability of reachability in alternating pushdown systems, showing that it is a simple consequence of a cut-elimination theorem for some natural-deduction style inference systems. Then, we show how this result can be used to extend an alternating pushdown system into a complete system where for every configuration , either or is provable.