Boolean logic: Difference between revisions

Revision as of 15:49, 27 February 2011

Revision as of 15:52, 27 February 2011

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* The '''empty set''' or '''null set''' is the set of no elements, denoted by <math>\varnothing</math> and sometimes 0.

* A '''unary operator''' applies to a single set. There isare only onetwo unary operator,operators. One is called logical '''NOT'''. It works by taking the [[complement (set theory)|complement]] with respect to the universe, i.e. the set of all elements under consideration. The other is the cardinality, which converts a set into a whole number, the number of elements. This is written as ''n(A)''.

* A '''binary operator''' applies to two sets. The basic binary operators are logical '''OR''' and logical '''AND'''. They perform the [[union (set theory)|union]] and [[intersection (set theory)|intersection]] of sets. The difference between sets, ''A-B'', is the set of all elements in ''A'' and not in ''B''. The cartesian product, ''A×B'' is the set of ordered pairs taking one element from ''A'' and one from ''B''.