Rather simple function returns curious result. Explanation requested.
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- Subject: [mg131384] Rather simple function returns curious result. Explanation requested.
- From: James Stein <mathgroup at stein.org>
- Date: Tue, 2 Jul 2013 00:48:42 -0400 (EDT)
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For reasons that escape me, the simple function below fails to return an empty List when n==2; Is this a bug? If not, what is the explanation? If the return value for n==2 is changed to an integer or a string, the function behaves as expected.(Of course, this bizarre function is the result of simplifying a more reasonable one.) Clear[ f ]; f [run : { List___ } ] := Module [ { n }, n = run // Length; If [ n != 2, Return [ n ] ]; Module [ { } , { } (* Return Empty List if n==2 *) ] ] ; f [ { } ] f [ { { } } ] f [ { { }, { } } ] f [ { { }, { }, { } } ] f [ { { }, { }, { }, { } } ] When I run the above, I get these four outputs: 0 1 Sequence[{}, {}][] 3 4
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