Abstract
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.
Original language | English |
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Pages (from-to) | 866-883 |
Number of pages | 18 |
Journal | Annals of Pure and Applied Logic |
Volume | 164 |
DOIs | |
Publication status | Published - 2013 |