Reversible pushdown transducers

Deterministic pushdown transducers are studied with respect to their ability compute reversible transductions, that is, transform inputs into outputs in a way. This means the also backward deterministic and thus able uniquely step computation back forth. The families of transductions computed classified regard four types length-preserving as well property working reversibly. It turns out accurate one case separating witness can be provided. For remaining it is possible establish equivalence both by proving stationary moves always removed transductions.