Using descent theory we give various forms of short five-lemma in protomodular categories, known in the case of exact protomodular categories. We also describe the situation where the notion of a semidirect product can be defined categorically.
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1991 MSC: 18G50,20J05,18C10.
Theory and Applications of Categories, Vol. 4, 1998, No. 2, pp 37-46.
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