17th Annual Symposium on Foundations of Computer Science (sfcs 1976) (1976)
Oct. 25, 1976 to Oct. 27, 1976
DOI Bookmark: http://doi.ieeecomputersociety.org/10.1109/SFCS.1976.2
Some of the questions posed by Baker, Gill, and Solovay  are here answered. The principal result is that there exists a recursive oracle for which the relativized polynomial hierarchy exists through the second level; that is, there is a recursive set B such that Σ2P,B ≠ π2P,B. It follows that Σ2P,B ⊂≠ Σ3P,B.
T. P. Baker and A. L. Selman, "A second step toward the polynomial hierarchy," 17th Annual Symposium on Foundations of Computer Science (sfcs 1976)(FOCS), vol. 00, no. , pp. 71-75, 1976.