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.).