Toward classifying unstable theories
| dc.creator | Shelah, Saharon | |
| dc.date | 1995-08-15 | |
| dc.date.accessioned | 2026-07-07T09:15:23Z | |
| dc.date.available | 2026-07-07T09:15:23Z | |
| dc.description | The paper deals with two issues: the existence of universal models of a theory T and related properties when cardinal arithmetic does not give this existence offhand. In the first section we prove that simple theories (e.g., theories without the tree property, a class properly containing the stable theories) behaves ``better'' than theories with the strict order property, by criterion from [Sh:457]. In the second section we introduce properties SOP_n such that the strict order property implies SOP_{n+1}, which implies SOP_n, which in turn implies the tree property. Now SOP_4 already implies non-existence of universal models in cases where earlier the strict order property was needed, and SOP_3 implies maximality in the Keisler order, again improving an earlier result which had used the strict order property. | |
| dc.identifier | https://arxiv.org/abs/math/9508205 | |
| dc.identifier | http://arxiv.org/abs/math/9508205 | |
| dc.identifier | Ann. Pure Appl. Logic 80 (1995), 229--255 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/152998 | |
| dc.subject | Logic | |
| dc.title | Toward classifying unstable theories | |
| dc.type | text |