Readme.txt The following files contains developments in Coq . PropasTypesUtf8Notation.v This file contains notations in UTF8 for propositions as types notions at the Set level. Author: Olov Wilander 2012. PropasTypesBasics_mod.v A collection of basic definition and lemmas for Propositions as types at the Set level. Author: Olov Wilander 2012 SwedishSetoids_mod.v SwedishSetoids_mod2.v This contains definitions and results relating to setoids where the equivalence relation has truth values in Set (and not in Prop as in the standard Coq library). The binary sum, binary product and the coequalizer constructions for the category of setoids are established. Author: Olov Wilander 2012. Modification 2 uses a different record structure for setoids to optimize speed. CZF_pure.v The Aczel model of CZF formalized. Main author: Olov Wilander 2012. (Some tactics do not work in Coq 8.4.) CZF_pure_plus_REA.v The Aczel model of CZF formalized extended with verification of REA. Author: Erik Palmgren 2013 (Some tactics do not work in Coq 8.4.) CZFU_extension.v The Aczel model of CZFU (CZF with atoms) and results about V-representable setoids. formalized. Author: Olov Wilander 2012. (Some tactics do not work in Coq 8.4.) CZF_and_set_categories.v CZF_and_set_categories_corrected.v This contains the constructions of the two categories of sets and a proof of their isomorphisms as described in the paper "Constructing categories and setoids of setoids in type theory" by Erik Palmgren and Olov Wilander 2013. (Some tactics do not work in Coq 8.4.) CZF&setoids.pdf The paper "Constructing categories and setoids of setoids in type theory" by Erik Palmgren and Olov Wilander 2013. families_of_setoids_and_LCCC.v Contains proofs for the fact that the setoids form a locally cartesian closed pretopos and in particular a locally cartesian closed category. Categories are here defined without assuming equality on objects (so called e-categories). The proof is using Pi- and Sigma-constructions for families of setoids. Author: Erik Palmgren 2012. CategoricalUniverse.v CategoricalUniverse_v2.v Contains a construction of a category of setoids and has equality on objects, and which is closed under pullbacks. This described in revised versions of the paper "Constructing categories and setoids of setoids in type theory" by Erik Palmgren and Olov Wilander 2013. Version 2 (E.P.) became considerably faster by reformatting the main records structures. Author: Erik Palmgren 2013, based on a formalization of Olov Wilander of an extensional universe of setoids. Generators.v Shows that in (Cat_from_family F) the terminal object is a strong generators whenever it is represented. (See "Constructing categories and setoids ofsetoids in type theory" by Erik Palmgren and Olov Wilander 2013. Author: Erik Palmgren 2013.