More on directed colimits of models
More on directed colimits of models
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有关模型有向余极限的更多信息
DOI：
10.1007/bf00878503
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发表时间：
1994
影响因子：
0.6
通讯作者：
J. Rosický
中科院分区：
文献类型：
--
作者：
J. Rosický
M. Richter证明了：当一个∑-结构类K具有有限的一阶公理化时，包含K ∈ Str ∑保持所有存在的有向余极限（见[7]）。我们将把这个结果推广到具有无穷大一阶公理化的∑-结构类。我们还将证明，作为范畴，这些类具有自然的特征。
M. Richter has proved that whenever a classK of ∑-structures has a finitary first-order axiomatization then the inclusionK ↪Str ∑ preserves all existing directed colimits (see [7]). We will generalize this result to classes of ∑-structures having an infinitary first-order axiomatization in a larger signature ∑′. We will also show that, as categories, these classes have a natural characterization.