We obtain semantic characterizations, holding for any Grothendieck site (C, J), for the models of a theory classified by a topos of the form Sh(C, J) in terms of the models of a theory classified by a topos [C^op, Set]. These characterizations arise from an appropriate representation of flat functors into Grothendieck toposes based on an application of the Yoneda Lemma in conjunction with ideas from indexed category theory, and turn out to be relevant also in different contexts, in particular for addressing questions in classical Model Theory.
|Data di pubblicazione:||2012|
|Titolo:||Yoneda representations of flat functors and classifying toposes|
|Rivista:||THEORY AND APPLICATIONS OF CATEGORIES|
|Codice identificativo ISI:||WOS:000321003600021|
|Parole Chiave:||Classifying topos; Yoneda lemma; flat functor; theory of presheaf type|
|Appare nelle tipologie:||Articolo su Rivista|