Basic subtoposes of the effective topos
نویسندگان
چکیده
We study the lattice of local operators in Hyland’s Effective Topos. We show that this lattice is a free completion under internal sups indexed by the natural numbers object, generated by what we call basic local operators. We produce many new local operators and we employ a new concept, sight, in order to analyze these. We show that a local operator identified by A.M. Pitts in his thesis, gives a subtopos with classical arithmetic.
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عنوان ژورنال:
- Ann. Pure Appl. Logic
دوره 164 شماره
صفحات -
تاریخ انتشار 2013