A Chomsky-Schützenberger-Stanley type characterization of the class of slender context-free languages

Slender context-free languages have a complete algebraic characterization by L. Ilie in [13]. In this paper we give another characterization of this class of languages. In particular, using linear Dyck languages instead of unrestricted ones, we obtain a Chomsky-Schützenberger-Stanley type characterization of slender context-free languages

Lingvistiset kieliopit, joilla on on hyvin matala kompleksisuus

We have presented an overview of the FSIG approach and related FSIG gram- mars to issues of very low complexity and parsing strategy. We ended up with serious optimism according to which most FSIG grammars could be decom- posed in a reasonable way and then processed efficiently.Peer reviewe

On inverse deterministic pushdown transductions

AbstractClasses of source languages which can be mapped by a deterministic pushdown (DPDA) transduction into a given object language (while their complement is mapped into the complement of the object language) are studied. Such classes of source languages are inverse DPDA transductions of the given object language. Similarly for classes of object languages. The inverse DPDA transductions of the Dyck sets are studied in greater detail: they can be recognized in deterministic storage (log n)' but do not comprise all context free languages; their emptiness problem is unsolvable and their closure under homomorphism constitutes the r.e. sets. For each object language L we can exhibit a storage hardest language for the class of inverse DPDA transductions of L; similarly for the classes of regular, deterministic context free, and context free object languages. Last, we classify the classes of inverse DPDA transductions of the regular, deterministic context free, context free and deterministic context sensitive languages

Coalgebraic characterizations of context-free languages

Article / Letter to editorLeiden Inst Advanced Computer Science