A Glimpse on Algebraic Set Theory

2016 ◽  
pp. 243-266
Keyword(s):  
2008 ◽  
Vol 156 (1) ◽  
pp. 123-159 ◽  
Author(s):  
Benno van den Berg ◽  
Ieke Moerdijk
Keyword(s):  

2008 ◽  
Vol 14 (3) ◽  
pp. 281-298 ◽  
Author(s):  
Steve Awodey

AbstractThis brief article is intended to introduce the reader to the field of algebraic set theory, in which models of set theory of a new and fascinating kind are determined algebraically. The method is quite robust, applying to various classical, intuitionistic, and constructive set theories. Under this scheme some familiar set theoretic properties are related to algebraic ones, while others result from logical constraints. Conventional elementary set theories are complete with respect to algebraic models, which arise in a variety of ways, such as topologically, type-theoretically, and through variation. Many previous results from topos theory involving realizability, permutation, and sheaf models of set theory are subsumed, and the prospects for further such unification seem bright.


2018 ◽  
Vol 222 (10) ◽  
pp. 3137-3181 ◽  
Author(s):  
Benno van den Berg ◽  
Ieke Moerdijk
Keyword(s):  

2009 ◽  
Vol 74 (3) ◽  
pp. 861-890 ◽  
Author(s):  
S. Awodey ◽  
N. Gambino ◽  
P. L. Lumsdaine ◽  
M. A. Warren

AbstractWe present a solution to the problem of denning a counterpart in Algebraic Set Theory of the construction of internal sheaves in Topos Theory. Our approach is general in that we consider sheaves as determined by Lawvere-Tierney coverages, rather than by Grothendieck coverages, and assume only a weakening of the axioms for small maps originally introduced by Joyal and Moerdijk, thus subsuming the existing topos-theoretic results.


2010 ◽  
pp. 18-37 ◽  
Author(s):  
Benno van den Berg ◽  
Ieke Moerdijk

2012 ◽  
Vol 105 (5) ◽  
pp. 1076-1122 ◽  
Author(s):  
Benno van den Berg ◽  
Ieke Moerdijk
Keyword(s):  

2005 ◽  
Vol 70 (3) ◽  
pp. 879-890 ◽  
Author(s):  
Claire Kouwenhoven-Gentil ◽  
Jaap van Oosten
Keyword(s):  

AbstractFollowing the book Algebraic Set Theory from André Joyal and Ieke Moerdijk [8], we give a characterization of the initial ZF-algebra, for Heyting pretoposes equipped with a class of small maps. Then, an application is considered (the effective topos) to show how to recover an already known model (McCarty [9]).


Author(s):  
Andri Joyal ◽  
Ieke Moerdijk
Keyword(s):  

2014 ◽  
Vol 14 (01) ◽  
pp. 1450005 ◽  
Author(s):  
Benno van den Berg ◽  
Ieke Moerdijk

We propose an extension of Aczel's constructive set theory CZF by an axiom for inductive types and a choice principle, and show that this extension has the following properties: it is interpretable in Martin-Löf's type theory (hence acceptable from a constructive and generalized-predicative standpoint). In addition, it is strong enough to prove the Set Compactness theorem and the results in formal topology which make use of this theorem. Moreover, it is stable under the standard constructions from algebraic set theory, namely exact completion, realizability models, forcing as well as more general sheaf extensions. As a result, methods from our earlier work can be applied to show that this extension satisfies various derived rules, such as a derived compactness rule for Cantor space and a derived continuity rule for Baire space. Finally, we show that this extension is robust in the sense that it is also reflected by the model constructions from algebraic set theory just mentioned.


Sign in / Sign up

Export Citation Format

Share Document