Uniformly erasable AFL

Abstract

The purpose of this paper is to show that a number of well-known families have property (*). In particular, we prove that the family of context-free languages does indeed have this property. In addition, we show that several familiar subfamilies of the context-free languages, such as the one-counter languages, have property (*). Finally, we show that there are families satisfying (*) which are not subfamilies of the context-free languages, for we prove that any family generated from one-letter languages has property (*), thereby extending a result of [17].