Mathematics – Logic
Scientific paper
2011-09-04
Mathematics
Logic
32 pages
Scientific paper
Using Butz and Moerdijk's topological groupoid representation of a topos with enough points, a `syntax-semantics' duality for geometric theories is constructed. The emphasis is on a logical presentation, starting with a description of the semantical topological groupoid of models and isomorphisms of a theory and a direct proof that this groupoid represents its classifying topos. Using this representation, a contravariant adjunction is constructed between theories and topological groupoids. The restriction of this adjunction yields a contravariant equivalence between theories with enough models and semantical groupoids. Technically a variant of the syntax-semantics duality constructed in [Awodey and Forssell, arXiv:1008.3145v1] for first-order logic, the construction here works for arbitrary geometric theories and uses a slice construction on the side of groupoids---reflecting the use of `indexed' models in the representation theorem---which in several respects simplifies the construction and allows for an intrinsic characterization of the semantic side.
Forssell Henrik
No associations
LandOfFree
Topological Representation of Geometric Theories does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Topological Representation of Geometric Theories, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Topological Representation of Geometric Theories will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-109038