Retreat bounded picture languages

On Reversal-Bounded Picture Languages

Kim, C. and I.H. Sudborough, On reversal-bounded picture languages, Theoretical Computer Science 104 (1992) 185-206. For an integer k >O, a k-reversal-bounded picture language is a chain-code picture language which is described by a language L over the alphabet R= {u,d,r, I} such that, for every word x in L, the number of alternating occurrences of r’s and I’s in x is bounded by k. It is shown ...

On Drawn Symbolic Picture Languages

Bounded Counter Languages

We show that deterministic finite automata equipped with k two-way heads are equivalent to deterministic machines with a single two-way input head and k− 1 linearly bounded counters if the accepted language is strictly bounded, i.e., a subset of a∗1a ∗ 2 · · · a ∗ m for a fixed sequence of symbols a1, a2, . . . , am. Then we investigate linear speed-up for counter machines. Lower and upper time...

Scope-Bounded Pushdown Languages

We study the formal language theory of multistack pushdown automata (Mpa) restricted to computations where a symbol can be popped from a stack S only if it was pushed within a bounded number of contexts of S (scoped Mpa). We show that scoped Mpa are indeed a robust model of computation, by focusing on the corresponding theory of visibly Mpa (Mvpa). We prove the equivalence of the deterministic ...

On Some Recognizable Picture-Languages

We show that the language of pictures over fa; bg, where all occurring b's are connected is recognizable, which solves an open problem in Mat98]. We generalize the used construction to show that monocausal deterministically recognizable picture languages are recognizable, which is surprisingly nontrivial. Furthermore we show that the language of pictures over fa; bg, where the number of a's is ...