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A comment on Seven Puzzles You Think You Must Not Have Heard Correctly (2006) [pdf]. Parent comment

Re:Seven Puzzles You Think You Must Not Have Heard Correctly... by agf on Monday August 29, 2016 @09:51AM (#12381806)
Re-read your scenario -- you have both box A and box C containing name B, but the problem statement says each name appears only once. So you can't get into cycles like this.
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Re:Seven Puzzles You Think You Must Not Have Heard Correctly... by rntz on Monday August 29, 2016 @09:52AM (#12381822)
Ah, of course! That guarantees there are no "tails"; every name (& box) is part of exactly one cycle. And this is then a property of cycles of permutations generally. Thanks!
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