A new characterization of Goursat categories
We present a new characterisation of Goursat categories in terms of special kind of pushouts, that we call Goursat pushouts. This allows one to prove that, for a regular category, the Goursat property is actually equivalent to the validity of the denormalised 3-by-3 Lemma. Goursat pushouts are also...
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| Format: | other |
| Language: | eng |
| Published: |
2010
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| Online Access: | http://hdl.handle.net/10316/13706 |
| Country: | Portugal |
| Oai: | oai:estudogeral.sib.uc.pt:10316/13706 |
| Summary: | We present a new characterisation of Goursat categories in terms of special kind of pushouts, that we call Goursat pushouts. This allows one to prove that, for a regular category, the Goursat property is actually equivalent to the validity of the denormalised 3-by-3 Lemma. Goursat pushouts are also useful to clarify, from a categorical perspective, the existence of the quaternary operations characterising 3-permutable varieties |
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