Affine geometry with S. Dowdy's ``trapezoid'' as primitive.
نویسندگان
چکیده
منابع مشابه
Trapezoid Graphs and Generalizations, Geometry and Algorithms
Trapezoid graphs are a class of cocomparability graphs containing interval graphs and permutation graphs as subclasses. They were introduced by Dagan et al. [3]. They propose an 0(n2) algorithm for chromatic number and a less efficient algorithm for maximum clique on trapezoid graphs. Based on a geometric representation of trapezoid graphs by boxes in the plane we design optimal, i.e., O(n log ...
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Necessary and sufficient conditions are given for a lattice L to be the lattice of flats of an affine space of arbitrary (possibly infinite) dimension. 1. Incidence spaces and Hilbert lattices. By an incidence space [Gl], we mean a system of points, lines, and planes satisfying Hilbert's Axioms of Incidence [Verknüpfung] [HI] as follows: (11) Any two distinct points determine a unique line. (12...
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ژورنال
عنوان ژورنال: Notre Dame Journal of Formal Logic
سال: 1970
ISSN: 0029-4527
DOI: 10.1305/ndjfl/1093893938