# Liu Yiqun: I Sigma_1 and d.c.e. construction on isolation pairs

Invitation to the Logic Seminar at the National University of Singapore

Date: Wednesday, 13 November 2013, 17:00 hrs (today)

Room: S17#04-06, Department of Mathematics, NUS

Speaker: Liu Yiqun

Title: I Sigma_1 and d.c.e. construction on isolation pairs

Abstract: In this talk, I am working in any nonstandard model of
P- + I Sigma_1 and construct a low d.c.e. set D which is
upward isolated by the Turing complete set K in c.e. sense.
I.e., K is the only c.e. set above D (which makes D proper d.c.e.).

URL: http://www.comp.nus.edu.sg/~fstephan/logicseminar.html