Timeline for Complexity of the statement 'P is proper'
Current License: CC BY-SA 2.5
3 events
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| Nov 6, 2010 at 9:03 | comment | added | Stefan Hoffelner | I considered this formulation first when I tried to answer the question, but I wasn't sure how to write : 'II has a winning strategy' in a correct way. However the formulation which I chose for my answer above isn't optimal as it leads to a $\Pi_3$ formula, which isn't best posssible according to Joel. I think that the first formulation of properness from theorem 2.8. in chapter III in Shelahs Proper Forcing book leads to a $Sigma_2$ formulation too, but it's rather annoying to really check it step by step. | |
| Nov 5, 2010 at 3:03 | history | edited | Amit Kumar Gupta | CC BY-SA 2.5 |
added 13 characters in body
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| Nov 5, 2010 at 2:41 | history | answered | Amit Kumar Gupta | CC BY-SA 2.5 |