Model Companions of T_σfor stable T
| dc.creator | Baldwin, John | |
| dc.creator | Shelah, Saharon | |
| dc.date | 2001-05-16 | |
| dc.date.accessioned | 2026-07-07T04:41:44Z | |
| dc.date.available | 2026-07-07T04:41:44Z | |
| dc.description | Let T be a complete first order theory in a countable relational language L . We assume relation symbols have been added to make each formula equivalent to a predicate. Adjoin a new unary function symbol sigma to obtain the language L_sigma; T_sigma is obtained by adding axioms asserting that sigma is an L-automorphism. We provide necessary and sufficient conditions for T_sigma to have a model companion when T is stable. Namely, we introduce a new condition: T_sigma admits obstructions, and show that T_sigma has a model companion iff and only if T_sigma does not admit obstructions. This condition is weakening of the finite cover property: if a stable theory T has the finite cover property then T_sigma admits obstructions. | |
| dc.identifier | https://arxiv.org/abs/math/0105136 | |
| dc.identifier | http://arxiv.org/abs/math/0105136 | |
| dc.identifier | Notre Dame J. Formal Logic 42 No. 3 (2001) 129--142 (2003) | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/61481 | |
| dc.subject | Logic | |
| dc.title | Model Companions of T_σfor stable T | |
| dc.type | text |