论文标题
关于半返回和拉姆西财产的新观点
A new perspective on semi-retractions and the Ramsey property
论文作者
论文摘要
我们研究了第二阶结构（通常在通常不同的签名中）之间的半回复的概念，这些结构是第二作者作为Ramsey属性与通用不可分化序列之间的联系。我们进一步在组合学和模型理论之间进行了这些联系，并通过新的镜头来查看半撤离，以在相当一般的条件下建立Ramsey特性的转移和有限的Ramsey学位，这是反例证明的最佳条件。最后，我们将半归因与预期的类别理论概念进行比较。
We investigate the notion of a semi-retraction between two first order structures (in typically different signatures) that was introduced by the second author as a link between the Ramsey property and generalized indiscernible sequences. We further these connections between combinatorics and model theory, and look at semi-retractions through a new lens establishing transfers of the Ramsey property and finite Ramsey degrees under quite general conditions that are optimal as demonstrated by counterexamples. Finally, we compare semi-retractions to the category theoretic notion of a pre-adjunction.
