Any solution which returns a pair of numbers that are in the list and represent a minimal distance from each other with respect to all other possible pairings is correct. We are comparing the distance between all possible number pairings, and returning a minimal one. So the following are all correct: 
nn(1,5,9,15) returns (1,5)
# or
nn(1,5,9,15) returns (5,9)
# or
nn(1,5,9,15) returns (9,5)

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I don't really understand the beginning of your question though. 
   MeowChow                                   
               s aamecha.s a..a\u$&owag.print

In reply to Re: (tye)Re2: (Golf) Nearest Neighbors by MeowChow
in thread (Golf) Nearest Neighbors by MeowChow

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