Using string languages to describe picture languages

Context-Sensitive String Languages and Eecognizable Picture Languages

The theorem stating that the family of frontiers of recognizable tree languages is exactly the family of context-free languages (see J. Mezei and J. B. Wright, 1967, Inform. and Comput. 11, 3 29), is a basic result in the theory of formal languages. In this article, we prove a similar result: the family of frontiers of recognizable picture languages is exactly the family of context-sensitive la...

String Processing Languages

In programming contexts, the term string usually refers to a sequence of characters. For example, ABC is a string of three characters. Strings are more prevalent in computing than is generally realized. In most cases, computer input is in the form of strings, e.g., commands entered at a terminal. Similarly, computer output is in the form of strings; printed lines are simply strings of character...

On Drawn Symbolic 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 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 ...