More on injectivity in locally presentable categories
| Authors | |
|---|---|
| Year of publication | 2002 |
| Type | Article in Periodical |
| Magazine / Source | Theory and Applications of Categories |
| MU Faculty or unit | |
| Citation | |
| Field | General mathematics |
| Keywords | locally presentable category; injectivity class |
| Description | Injectivity with respect to morphisms having k-presentable domains and codomains is characterized: such injectivity classes are precisely those closed under products, k-directed colimits and k-pure subobjects. This sharpens the result of the first two authors. In contrast, for geometric logic an example is found of a class closed under directed colimits and pure subobjects, but not axiomatizable by a geometric theory. |
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