Minimal cover-automata for finite languages

AbstractA cover-automaton A of a finite language L⊆Σ∗ is a finite deterministic automaton (DFA) that accepts all words in L and possibly other words that are longer than any word in L. A minimal deterministic finite cover automaton (DFCA) of a finite language L usually has a smaller size than a minimal DFA that accept L. Thus, cover automata can be used to reduce the size of the representations of finite languages in practice. In this paper, we describe an efficient algorithm that, for a given DFA accepting a finite language, constructs a minimal deterministic finite cover-automaton of the language. We also give algorithms for the boolean operations on deterministic cover automata, i.e., on the finite languages they represent

A class of measures on formal languages

In this paper we introduce a class of measures on formal languages. These measures are based on the number of different ways a string of a specified finite length can be completed to obtain strings of the language. The relation with automata and grammars is established, and the polynomial measure, a special case of the general notion, is studied in detail. We give some closure properties for well-known operations on languages, and finally, we prove that the class of polynomial measurable languages is a Pre-AFL. © 1977 Springer-Verlag.SCOPUS: ar.jinfo:eu-repo/semantics/publishe