Which classes of structures are both pseudo-elementary and definable by an infinitary sentence?
| dc.contributor.author | Boney, Will | |
| dc.contributor.author | Csima, Barbara F. | |
| dc.contributor.author | Day, Nancy A. | |
| dc.contributor.author | Harrison-Trainor, Matthew | |
| dc.date.accessioned | 2020-07-07T15:46:24Z | |
| dc.date.available | 2020-07-07T15:46:24Z | |
| dc.date.issued | 2019-03-21 | |
| dc.description.abstract | When classes of structures are not first-order definable, we might still try to find a nice description. There are two common ways for doing this. One is to expand the language, leading to notions of pseudo-elementary classes, and the other is to allow infinite conjuncts and disjuncts. In this paper we examine the intersection. Namely, we address the question: Which classes of structures are both pseudo-elementary and Lω1,ω-elementary? We find that these are exactly the classes that can be defined by an infinitary formula that has no infinitary disjunctions. | en |
| dc.description.sponsorship | Natural Sciences and Engineering Research Council Discovery Grant 312501 || Natural Sciences and Engineering Research Council Banting Fellowship | en |
| dc.identifier.uri | http://hdl.handle.net/10012/16042 | |
| dc.language.iso | en | en |
| dc.title | Which classes of structures are both pseudo-elementary and definable by an infinitary sentence? | en |
| dc.type | Technical Report | en |
| uws.contributor.affiliation1 | Faculty of Mathematics | en |
| uws.contributor.affiliation2 | David R. Cheriton School of Computer Science | en |
| uws.contributor.affiliation2 | Pure Mathematics | en |
| uws.peerReviewStatus | Unreviewed | en |
| uws.scholarLevel | Faculty | en |
| uws.scholarLevel | Post-Doctorate | en |
| uws.typeOfResource | Text | en |