Current List of Publications

The older publications are not available electronically; please contact me for hard copy.

*Realizability Models Separating Various Fan Theorems*, joint with Michael Rathjen,**Proceedings, Computability in Europe 2013**(Bonizzoni, Brattka, and Loewe, eds.): Available in pdf format.*Separating the Fan Theorem and Its Weakenings*, joint with Hannes Diener, in**Proceedings of LFCS '13, Lecture Notes in Computer Science #7734**(Sergei N. Artemov and Anil Nerode, eds.), Springer, 2013, pp. 280-295: Available in pdf, dvi, and ps formats. Also available, along with the BD-N results in the following paper, as slides.*Principles Weaker than BD-N*, joint with Hannes Diener,**Journal of Symbolic Logic**, 78, No. 3 (2013): Available in pdf, dvi, and ps formats. Also available, along with the Fan Theorem results in the preceding paper, as slides.*Walker's Cancellation Theorem*, joint with Fred Richman,**Communications in Algebra**, to appear: Available in pdf format.*The Kripke Schema in Metric Topology*, joint with Fred Richman and Peter Schuster,**Mathematical Logic Quarterly**, 58, No. 6 (2012), p. 498-501, doi: 10.1002/malq.201200018: Available in pdf format.*On the Structure of Honest Elementary Degrees*, joint with Lars Kristiansen, Jan-Christoph Schlage-Puchta, and Andreas Weiermann,**Proceedings of the 2009-2011 CRM Infinity Project**: Available in pdf format.*Feedback ITTMs and Sigma-0-3-Determinacy*: Available as slides.*On the Failure of BD-N*,**Journal of Symbolic Logic**, 78, No. 1 (2013), pp. 39-56: Available in pdf, dvi, and ps formats. Also available as slides.*Geometric Spaces with No Points*,**Journal of Logic and Analysis**, http://logicandanalysis.org/, 2, No. 6 (2010), pp. 1-10, doi 10.4115/jla2010.2.6: Available in pdf, dvi, and ps formats. Also available as slides.*Zero Sets of Univariate Polynomials*, joint with Fred Richman,**Transaction of the AMS**, 362 (2010), pp. 6619-6632: Available in pdf and dvi formats. Also available as slides under the name "The Weak Fundamental Theorem of Algebra."*Topological Forcing Semantics with Settling*,**Proceedings of LFCS '09, Lecture Notes in Computer Science**(Sergei N. Artemov and Anil Nerode, eds.), Springer, 2009; also**Annals of Pure and Applied Logic**, 163 (2012), pp. 820-830, doi 10.1016/j.apal.2011.09.014: Available in pdf, dvi, and ps formats, and as slides.*Well-founded Iterations of Infinite Time Turing Machines*, in**Ways of Proof Theory**(Ralf Schindler, ed.), Ontos, 2010: Available in pdf, dvi, and ps formats, and as slides.*Signed-Bit Representations of Real Numbers*, joint with Fred Richman,**Journal of Logic and Analysis**, http://logicandanalysis.org/, 1, No. 18 (2009), pp. 1-18, doi 10.4115/jla.2009.1.10: Available in pdf, dvi, and ps formats, and as slides.*On the Constructive Dedekind Reals*, joint with Michael Rathjen,**Proceedings of LFCS ’07, Lecture Notes in Computer Science #4514**(Sergei N. Artemov and Anil Nerode, eds.), Springer, 2007, pp. 349-362, also**Logic and Analysis**, 1, No. 2 (2008), pp. 131-152: Available in pdf, dvi, and ps formats. (The journal**Logic and Analysis**is now accessible via the website for**The Journal of Logic and Analysis**here.)*On the Cauchy Completeness of the Constructive Cauchy Reals*,**Mathematical Logic Quarterly**, 53, No. 4-5 (2007), pp. 396-414: Available in pdf, dvi, and ps formats.*CZF and Second Order Arithmetic*,**Annals of Pure and Applied Logic**, 141 (2006), pp. 29-34: Available in pdf, dvi, and ps formats.-
*Independence Results around Constructive ZF*,**Annals of Pure and Applied Logic**, 132, No. 2-3 (2005), pp. 209-225: Available in pdf, dvi, and ps formats. -
*On the Regular Extension Axiom and Its Variants*(joint with Michael Rathjen),**Mathematical Logic Quarterly**, 49, No. 5 (2003), pp. 511-518: Available in pdf format; see also Rathjen's home page. -
*IKP and Friends*,**Journal of Symbolic Logic**, 67 (2002), pp. 1295-1322: Available in pdf, dvi, and ps formats. *Intuitionistic L*, in**Logical Methods in Computer Science: The Nerode Conference**(Crossley et al., eds.), Birkhauser, 1993, pp. 555-571: Available here.*μ-definable Sets of Integers*,**Journal of Symbolic Logic**, 58 (1993), pp. 291-313*An Introduction to γ-recursion Theory*,**Journal of Symbolic Logic**, 55 (1990), pp. 194-206*μ-definable Sets of Integers*,**Proceedings of the 4th Annual Symposium on Logic in Computer Science**, IEEE Computer Society Press, 1989, pp. 343-352*There's No Forcing a Least Uper Bound*,**Proceedings of the American Mathematical Society**, 105 (1989), pp. 998-1002*Sacks Forcing Sometimes Needs Help to Produce a Minimal Upper Bound*,**Journal of Symbolic Logic**, 54 (1989), pp. 490-498*Definability and Initial Segments of c-degrees*,**Journal of Symbolic Logic**, 53 (1988), pp. 1070-1081*Admissibility Spectra and Minimality*,**Annals of Pure and Applied Logic**, 40 (1988), pp. 257-276*Playing with Admissibility Spectra*,**Israel Journal of Mathematics**, 63 (1988), pp. 243-256*Another Extension of Van de Wiele's Theorem*,**Annals of Pure and Applied Logic**, 38 (1988), pp. 301-306*Hook-up Security and Generalized Restrictiveness*,**Proceedings of the 12th National Computer Security Conference**, Baltimore, pp. 111-122*The SDOS Project -- Verifying Hook-Up Security*,**Proceedings of the 1987 Aerospece Computer Security Conference**, Orlando, Florida , AIAA (with Doug Weber)*Simple R.E. Degree Structures*,**Journal of Symbolic Logic**, 52 (1987), pp. 203-213*Uncountable Master Codes and the Jump Hierarchy*,**Journal of Symbolic Logic**, 52 (1987), pp. 952-958*Lattices of c-degrees*,**Annals of Pure and Applied Logic**, 36 (1987), pp. 115-118*Admissibility Spectra through Aleph-1*,**Israel Journal of Mathematics**, 60 (1987), pp. 225-235