Ronald Harrop. A relativization procedure for propositional calculi, with an application to a generalized form of Post's theorem. Proceedings of the London Mathematical Society, vol. 14 (1964), pp. 595–617. - Ronald Harrop. Some generalizations and applications of a relativization procedure for propositional calculi. Formal systems and recursive functions, Proceedings of the Eighth Logic Colloquium, Oxford, July 1963, edited by J. N. Crossley and M. A. E. Dummett, Studies in logic and the foundations of mathematics, North-Holland Publishing Company, Amsterdam1965, pp. 12–41.
1967 ◽
Vol 32
(1)
◽
pp. 125-126