Embeddings and absolute retracts of relational systems. (English) Zbl 0973.03067
Summary: For a class \(\mathcal K\) of relational \(\Delta\)-systems we study two related problems: 1) the embeddability of objects of \(\mathcal K\) into direct products or powers of certain simple members of \(\mathcal K\), 2) the absolute retracts in \(\mathcal K\) (considered as a category whose morphisms are all relational homomorphisms).
MSC:
| 03E20 | Other classical set theory (including functions, relations, and set algebra) |
| 08A02 | Relational systems, laws of composition |
| 08B25 | Products, amalgamated products, and other kinds of limits and colimits |
| 18B10 | Categories of spans/cospans, relations, or partial maps |
