Analysis of algorithms for the recognition of rational and context-free trace languages

The previous algorithm can be used to design a simple u.r.g. for inherently ambiguous context-free languages which works in polynomial time whenever the ambiguity of the grammar

Rational relations on finite words were studied in the sixties and played a fun- damental role in the study of families of context free languages [Ber79]. Their extension to

signature the Fibonacci word (cf. Section 4); and the rational base numeration systems as defined in [1] and whose representation languages have periodic signa- tures, that

It turned out that the omega languages accepted by omega pushdown automata were also those generated by context free grammars where infinite derivations are considered , also studied

We show that the Borel hierarchy of the class of context free ω-languages, or even of the class of ω-languages accepted by B¨ uchi 1-counter automata, is the same as the Borel

In previous papers, we proved that there are context free ω-languages, accepted by B¨ uchi or Muller pushdown automata, of every finite Borel rank, of infinite Borel rank, or even

free languages (accepted by pushdown automata with a B¨ uchi or Muller acceptance con- dition) exhaust the finite ranks of the Borel hierarchy, [Fin01a], that there exist some

Keywords: Infinite words; pushdown automata; context-free (ω)-languages; ω-powers; Cantor topology; topological complexity; Borel hierarchy; Wadge hierarchy; complete sets;