2009/05/26 by P. D. Welch, Welch, P. D.
Mathematics · #03E45 03F45 03E60 03E15 #FOS: Mathematics #Logic (math.LO) #math.LO #msc:03E15 #msc:03E45 #msc:03E60 #msc:03F45
paper · pdf · doi:10.48550/arxiv.0905.4412
submitted; this is a revised version of an unsubmitted July 2003 preprint, now with a minimally improved upper bound
arxiv created 2009/05/26 · arxiv updated 2009/12/01
We locate winning strategies for various Sigma03-games in the L-hierarchy in order to prove that Sigma03 Determinacy is intermediate between Pi13-CA0 (even Pi12-CA0 (lightface) with Pi13-lightface definable parameters allowed) and Delta13-CA0 + AQI. (Here "AQI" is the statement in second order number theory that every arithmeical quasi-inductive definition on any input stabilizes).