In this paper we discuss still another version of indexed grammars ¹ and macro grammars³,gaining some geometric intuition about the structure of these systems. An ordinary context-free grammar is a rewriting system for strings; we find that a macro ...

Group events are defined as regular events recognized by partial group automata. Canonical forms are introduced for the class of regular expressions denoting group events. Algorithms are presented to find a canonical form from a recognizing automaton, ...

Two schemes for the specification of translations on a context-free grammar are proposed. The first scheme, called a generalized syntax directed translation (GSDT), consists of a context free grammar with a set of semantic rules associated with each ...