Sharps, pistols, and the \Sigma^1_3 correctness of K

17.01.2002 15:00 - 16:30

R. Schindler (U Wien)

I'll give a simple proof of the following result of Steel and Welch: Let \(x\) be a solution to the \(\Pi^1_2\) property \(\Phi(-)\), and suppose that \(x^\sharp\), \(x^{\sharp\sharp}\), \(x^{\sharp\sharp\sharp}\), etc. exist; suppose further that \(0^{¶}\) doesn't exist. Then \(K\) contains a solution to \(\Phi(-)\).

Organiser:

KGRC

Location:
SR 101, 2. St., Währinger Str. 25