Minimal Counterexamples and Minimal Logic

Peter Schuster

(University of Leeds)

In many a proof by contradiction of a universal statement the existence of a minimal counterexample is proved by the Lemma of Kuratowski-Zorn.
Whenever minimal logic suffices for establishing the hypotheses, one can reread the proof as a direct and inductive proof with the principle of Open Induction by Jean-Claude Raoult.

(This work was prompted by a communication by Ulrich Berger.)

Monday 17th March 2014, 16:00
Robert Recorde Room
Department of Computer Science