Almost-Everywhere Complexity Hierarchies for Nondeterministic Time

A preliminary version of this work appeared as [2]. y Supported in part by National Science Foundation grant CCR-9000045. Some of this research was performed while the author was a visiting professor at Institut f ur Informatik, Universit at W urzburg, D-8700 W urzburg, Federal Republic of Germany. z Supported in part by the National Science Foundation grants CCR-8808949 and CCR-8958528. Work done in part while at the Johns Hopkins University. x Supported in part by National Science Foundation grants MIP-8608137 and CCR-8814339, National Security Agency grant MDA904-87-H, and a Fulbright-Hays research fellowship. Some of this research was performed while the author was a Guest Professor at Mathematisches Institut, Universit at Heidelberg.