An Isomorphism between Abstract Polyhedral Cones and De nite Boolean Functions
نویسندگان
چکیده
Polyhedral cones can be represented by sets of linear inequalities that express inter-variable relationships. These inequalities express inter-variable relationships that are quantiied by the ratios between the variable coeecients. However, linear inequalities over a non-negative variable domain with only unit variable coeecients and no constants other than zero can represent relationships that can be valid in non-numeric domains. For instance, if variables are either non-negative or zero itself, that is, a strictly two-point domain, then f0 x; 0 y; x yg; expresses a dependency between x and y; since if y is known to be zero, then so is x: By deening an abstraction operator that eeectively puts aside the scaling coeecients whilst retaining the inter-variable aspect of these relationships polyhedral cones can express the same dependency information as Def , a class of Boolean function. Boolean functions are considered over a xed nite set of variables and Def is a subset of the positive Boolean functions, which return the value true when every variable returns true: Def is a complete lattice ordered by logical consequence and it will be shown that the abstract cones also form a complete lattice, ordered by set inclusion, that is isomorphic to Def :
منابع مشابه
Citation for published version Benoy , Florence and King , Andy ( 1999 ) An Isomorphism between Abstract Polyhedral Cones
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