A Note Concerning Nondeterministic Tape Complexities

Abstract

A set of sufficient conditions on tape functions Ll(n) and L2(n) is presented that guarantees the existence of a set accepted by an Ll(n)-tape bounded nondeterministic Turing machine, but not accepted by any L~(n)-tape bounded nondeterministic Turing machine. Interesting corollaries arise. For example, it is shown that, for integers m ; 0, p ;1, and q ; 1, there is a set accepted by an [n~+(P/q)]-tape bounded nondeterministic Turing machine that is not accepted by any [nm+(p/(q+l))]-tape bounded nondeterministic Turing machine. © 1972, ACM. All rights reserved.