Document Type

Technical Report

Publication Date

Summer 7-1-1974


This paper is concerned with deterministic ETOL languages. A theorem is proved which, roughly speaking, says that if an ETOL language contains a word which a special property then it must contain an infinite set of words obtained from the given one by “synchronously pumping” a number of subwords of the given word. This theorem has numerous applications for proving that certain languages are not deterministic ETOL languages.