Abstract
Partially ordered sets are described in terms of partial operations with equationally defined domains and equations, thus the categoryPOS of posets is represented as a one-sorted essentially algebraic category in the sense of Freyd [7] which, in this case even can be fully embedded into a non-trivial variety. This is achieved by using the relation of a poset rather than its underlying set as the carrier set of the algebraic structure. Essentially equational descriptions of somePOS-based algebraic structures are given, and an equational characterization of Galois connections is obtained.
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The author gratefully acknowledges the hospitality of the Department of Mathematics, Applied Mathematics and Astronomy at UNISA, where this note was written during an extended visit.
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Porst, HE. The algebraic theory of order. Appl Categor Struct 1, 423–440 (1993). https://doi.org/10.1007/BF00872943
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DOI: https://doi.org/10.1007/BF00872943