Logic Collogquium '80 : papers intended for the European summer meeting of the Association for Symbolic Logic

The papers appearing in this volume are part of those originally intended for presentation at the conference: Logic Colloquium'80 - European Summer Meeting of the Association for Symbolic Logic (A.S.L.) which was to takeplace in Prague, August 24·30, 1980, principally under the auspices of the Czech Academy of Sciences. There were 36 invited speakers from Western and Eastern Europe, Israel, the U.S., and the U.S.S.R. The local organizingcommittee cabled participants on July 15, 1980 to inform them that the meeting was cancelled for technical reasons; a subsequent communication stated that the cancellation was due to unforeseen circumstances lying beyond the controlof the organizing committee. The unexpected cancellation of the Prague meeting was greatly regretted, since so much care, time, and energy had been given to its advance preparation by the local organizing committee as well as by representatives of the A.S.L.and its European Committee. The late date on which cancellation took place required drastic changes of plans by speakers and participants. Last-minute efforts to reschedule the meeting elsewhere in Europe could not be realized. Content: Edited by Page iii Copyright Page Page iv Preface Pages v-vi Solomon Feferman Editors' Note Page vii D. Van Dalen, D. Lascar, T. Smiley Strong Decomposability of Ultrafilters I Original Research Article Pages 1-10 Bohuslav Balcar, Petr Simon Problematic Principles in Constructive Mathematics Original Research Article Pages 11-55 Michael J. Beeson Modeles Recursivement Satures De L'addition Et De La Multiplication Des Entiers Naturels Original Research Article Pages 57-68 Patrick Cegielski, Kenneth Mcaloon, George Wilmers Quantifier Eliminable Groups Original Research Article Pages 69-81 Gregory Cherlin, Ulrich Felgner Singleton Reals Original Research Article Pages 83-94 D. van Dalen Inductively Presented Systems and the Formalization of Meta-Mathematics Original Research Article Pages 95-128 Solomon Feferman Limitations to Mathematical Knowledge Original Research Article Pages 129-146 R.O. Gandy Counting Equivalence Classes For Co-Оє-Souslin Equivalence Relations Original Research Article Pages 147-152 Leo Harrington, Saharon Shelah On Silver's and Related Principles Original Research Article Pages 153-172 Akihiro Kanamori AN (в„μ 2 , в„μ 2 , в„μ 0 ) - SATURATED IDEAL ON О© 1 Original Research Article Pages 173-180 Richard Laver The Universal Splitting Property: I Original Research Article Pages 181-207 M. Lerman, J.B. Remmel How Weak is A Closed Unbounded Ultrafilter? Original Research Article Pages 209-230 William Mitchell The Turing and Truth-Table-Degrees are not Elementarily Equivalent Original Research Article Pages 231-237 Richard A. Shore ОЈ 1 and О 1 Transfinite Induction Original Research Article Pages 239-253 Stephen G. Simpson Set Theoretic Aspects of Atr 0 Original Research Article Pages 255-271 Stephen G. Simpson Back-and-Forth Inside A Recursively Saturated Model of Arithmetic Original Research Article Pages 273-278 C. SmoryЕ„ski Intuitionistic Extensions of the Reals II Original Research Article Pages 279-310 A.S. Troelstra On Core Structures for Peano Arithmetic Original Research Article Pages 311-314 A.J. Wilkie Unions of Zf - -Models Which are Themselves Zf - -Models Original Research Article Pages 315-342 Andrzej Zarach