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equivalence_relation [2013/05/23 17:19] nikolaj |
equivalence_relation [2014/03/21 11:11] |
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- | ===== Equivalence relation ===== | ||
- | ==== Definition ==== | ||
- | | $X$ | | ||
- | | $ \sim \in\text{Rel}(X) $ | | ||
- | ^ $ \sim \in \text{EquivRel}(X) $ ^ | ||
- | |||
- | The relation $R$ is an equivalence relation, if it's in the intersection of all reflexive, all symmetric and all transitive relation. Hence | ||
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- | ^ $ \forall_{\text{dom}(\sim)} x\ (\langle x,x\rangle \in \sim) $ ^ | ||
- | ^ $ (\langle x,y\rangle \in \sim) \Leftrightarrow (\langle y,x\rangle \in \sim) $ ^ | ||
- | ^ $ (\langle x,y\rangle \in \sim) \land (\langle y,z\rangle \in \sim) \Leftrightarrow (\langle x,z\rangle \in \sim) $ ^ | ||
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- | ==== Ramifications ==== | ||
- | === Reference === | ||
- | Wikipedia: [[http://en.wikipedia.org/wiki/Equivalence_relation|Equivalence relation]] | ||
- | ==== Context ==== | ||
- | === Subset of === | ||
- | [[Reflexive relation]], [[Symmetric relation]], [[Transitive relation]] |