STRICT LOCAL TESTABILITY OF THE FINITE CONTROL OF TWO-WAY AUTOMATA AND OF REGULAR PICTURE DESCRIPTION LANGUAGES

Abstract

We prove that every regular language is recognized by a deterministic two-way finite automaton whose control unit is strictly locally testing. Similarly, every picture language which can be described by a regular language can actually be described by a strictly locally testable language; this strengthens a result of Friedhelra Hinz.