Abstract
In this paper we want to investigate two notions of the cardinality of relations in the context of allegories. The different axiom systems are motivated on the existence of injective and surjective functions, respectively. In both cases we provide a canonical cardinality function and show that it is initial in the category of all cardinality functions over the given allegory.
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Kawahara, Y., Winter, M. (2008). Cardinality in Allegories. In: Berghammer, R., Möller, B., Struth, G. (eds) Relations and Kleene Algebra in Computer Science. RelMiCS 2008. Lecture Notes in Computer Science, vol 4988. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-540-78913-0_21
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DOI: https://doi.org/10.1007/978-3-540-78913-0_21
Publisher Name: Springer, Berlin, Heidelberg
Print ISBN: 978-3-540-78912-3
Online ISBN: 978-3-540-78913-0
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