Abstract. We introduce the synchronization of a pushdown automaton by a sequential transducer associating an integer to each input word. The visibly pushdown automata are the autom...
Abstract. Tree series transformations computed by polynomial topdown and bottom-up tree series transducers are considered. The hierarchy of tree series transformations obtained in ...
We introduce -synchronous relations for a rational number . We show that if a rational relation is both - and -synchronous for two different numbers and , then it is recognizab...