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| | Dedekind cut - Encyclopedia.WorldSearch (Site not responding. Last check: 2007-10-21) |
 | | In mathematics, a Dedekind cut in a totally ordered set S is a partition of it, (A, B), such that A is closed downwards (meaning that for any element x in S, if a is in A and x ≤ a, then x is in A as well) and B is closed upwards. |
 | | For example it is shown that the typical Dedekind cut in the real numbers is either a pair with A the interval (−∞, a), in which case B must be |
 | | is a Dedekind cut we could call (−∞, a); by identifying a with it, the linearly ordered set S is embedded in the set of all Dedekind cuts of S. If the linearly ordered set S does not enjoy the least-upper-bound property, then the set of Dedekind cuts will be strictly bigger than S. |
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