Glueing Analysis for Complemented Subtoposes Anders Kock and till Plewe

Glueing Analysis for Complemented Subtoposes

We prove how any (elementary) topos may be reconstructed from the data of two complemented subtoposes together with a pair of left exact “glueing functors”. This generalizes the classical glueing theorem for toposes, which deals with the special case of an open subtopos and its closed complement. Our glueing analysis applies in a particularly simple form to a locally closed subtopos and its com...

Local fibred right adjoints are polynomial

ANDERS KOCK and JOACHIM KOCK Mathematical Structures in Computer Science / Volume 23 / Issue 01 / February 2013, pp 131 ­ 141 DOI: 10.1017/S0960129512000217, Published online: Link to this article: http://journals.cambridge.org/abstract_S0960129512000217 How to cite this article: ANDERS KOCK and JOACHIM KOCK (2013). Local fibred right adjoints are polynomial. Mathematical Structures in Computer...

The Osculating Plane of a Space Curve - Synthetic Formulations

One More Notion of Relative Booleanness

We investigate a condition on geometric morphisms which is strictly intermediate between relative Booleanness conditions previously studied by Kock and Reyes.

Every hendue comes from a local equivalence relation

Kock, A. and I. Moerdijk, Every &endue comes from a local equivalence relation, Journal of Pure and Applied Algebra 82 (1992) 155-174. We first prove that, under suitable connectedness assumptions, the equivariant sheaves for a local equivalence relation on a space (or a locale) form an &endue topos. Our main result is that conversely, every &endue can be obtained in this way.