Short Extenders Forcings II
نویسنده
چکیده
A model with otp(pcf(a)) = ω1 + 1 is constructed, for countable set a of regular cardinals. 1 Preliminary Settings Let 〈κα | α < ω1〉 be an an increasing continuous sequence of singular cardinals of cofinality ω so that for each α < ω1, if α = 0 or α is a successor ordinal, then κα is a limit of an increasing sequence 〈κα,n | n < ω〉 of cardinals such that (1) κα,n is strong up to a 2-Mahlo cardinal < κα,n+1,
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تاریخ انتشار 2011