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Optimum basis of finite convex geometry
Convex geometries form a subclass of closure systems with unique criticals, or \(UC\)-systems. We show that the \(F\)-basis introduced in [1] for \(UC\)-systems, becomes optimum in convex geometries, in two essential parts of the basis: right sides (conclusions) of binary implications and left sides...
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Published in: | arXiv.org 2016-01 |
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Format: | Article |
Language: | English |
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Online Access: | Get full text |
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Summary: | Convex geometries form a subclass of closure systems with unique criticals, or \(UC\)-systems. We show that the \(F\)-basis introduced in [1] for \(UC\)-systems, becomes optimum in convex geometries, in two essential parts of the basis: right sides (conclusions) of binary implications and left sides (premises) of non-binary ones. The right sides of non-binary implications can also be optimized, when the convex geometry either satisfies the Carousel property, or does not have \(D\)-cycles. The latter generalizes a result of P.L.~Hammer and A.~Kogan for acyclic Horn Boolean functions. Convex geometries of order convex subsets in a poset also have tractable optimum basis. The problem of tractability of optimum basis in convex geometries in general remains to be open. [1] K. Adaricheva and J.B.Nation, On implicational bases of closure systems with unique critical sets, arxiv:1205.2881 |
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ISSN: | 2331-8422 |