It is proved that given an E0L form F it is decidable whether or not F is vomplete. The concept of n-completeness, n a positive integer, is introduced and it is shown that for an E0L form F and an integer n?2 vompleteness is equivalent with n-completeness.

Vompleteness of E0L forms is decidable

This paper presents a systematic investigation of the basic axioms of the theory of E0L forms, in particular it continues the research from Rozenberg and Verraedt. Three new interpretation mechanisms—fixed, terminal fixed and nonterminal fixed interpretations—are introduced and extensively studied. When compared with terminal invariant and nonterminal invariant interpretations from Rozenberg and Verraedt these interpretations constitute a natural “next step” towards increasing the similarity of the “master” E0L form with its interpretations. In particular it is shown that each (ordinary) E0L family is a nonterminal fixed E0L family. It is also proved that for each of the new defined interpretation mechanisms the form equivalence problem is undecidable.

On fixed, terminal fixed and nonterminal fixed interpretations of E0L forms

The goodness of {S,a}-EOL forms is decidable

Abstract A general mathematical framework to deal with (the decidability status of) properties of derivations in E0L systems (forms) is developed. It is based on the theory of well-quasi-orders. This paper (the first of two parts) deals with the mathematical theory of the proposed approach.

Verraedt

Papers

Basic Formulas and Languages Part I. The Theory ; CU-CS-191-80

Basic Formulas and Languages Part II. Applications to EOL Systems and Forms ; CU-CS-192-80