| Résume | We propose a model theory for directed limits and colimits of first-order structures, motivated by applications to commutative algebra and the model theory of valued fields. The treatment emphasises the natural assumption that transition maps are definable in a suitable sense.
Time permitting, I will explain connections to other approaches to this topic, including infinitary logic, Feferman’s local functors, ultraproducts, and pro- and ind-definable sets. |
