Generalized theorems on the relationships among reducibility notions to certain complexity classes. 26 M. Ogiwara and L. Hemachandra. A complexity theory for feasible closure properties. 27 M. Ogiwara, T. Thierauf, S. Toda, and O. Watanabe. 28 S. Toda and M. Ogiwara.
Counting classes are at least as hard as the polynomial-time hierarchy.