The Strength of Some Combinatorial Principles Related to Ramsey's Theorem for Pairs

Denis R. Hirschfeldt, Carl G. Jockusch, Bjørn Kjos-Hanssen +2

We study the reverse mathematics and computability-the\-o\-re\-tic strength of (stable) Ramsey's Theorem for pairs and the related principles COH and DNR. We show that SRT${}_2^2$ im…