Error detection in formal languages

Comment on the Paper "Error Detection in Formal Languages"

In a paper of W. B. Smith [1], some normal form theorems have been presented about context-sensitive grammars. Professor A. Salomaa has noticed that the proof of Lemma 2 in this paper was incorrect and he has given an example in which the proof does not work. 1 It was guessed that there was no simple way to repair Smith's proof, while M. Penttonen has found a rather complicated proof of a somew...

Maximal Error-Detecting Capabilities of Formal Languages

A (combinatorial) channel is a set of pairs of words describing all the possible inputoutput channel situations. We introduce the concept “maximal error-detecting capability” of a given language, with respect to a certain class of channels, which is simply a maximal channel for which the given language is error-detecting. The new concept is intended to address formally the question of “finding ...

Error Detection Tools for Parallel Languages

Debugging and finding errors in parallel programs is a non-trivial task. It becomes even harder when computation units (threads or processes) communicate with one another using one-sided operations: the memory held in a computation unit’s memory can be accessed by another thread without any notification. In this paper we present a framework for detecting errors in distributed applications that ...

Factorization in Formal Languages

We consider several novel aspects of unique factorization in formal languages. We reprove the familiar fact that the set uf(L) of words having unique factorization into elements of L is regular if L is regular, and from this deduce an quadratic upper and lower bound on the length of the shortest word not in uf(L). We observe that uf(L) need not be context-free if L is context-free. Next, we con...

Formal Languages