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Distinquishing #'s in nested pure functions

• To: mathgroup at smc.vnet.net
• Subject: [mg126249] Distinquishing #'s in nested pure functions
• From: "Dave Snead" <dsnead6 at charter.net>
• Date: Fri, 27 Apr 2012 06:48:11 -0400 (EDT)
• Delivered-to: l-mathgroup@mail-archive0.wolfram.com
• References: <201204260933.FAA05752@smc.vnet.net>

Hi,

Is there a way to distinguish the #'s in nested pure functions?

As a simple example:

f[x_, y_] := x - y

Select[{1, 2, 3}, (f[#, #] & /@ {-1, -2, -3}) == {3, 4, 5} &]

I want the 1st # to correspond with the outer & (the equal)
and the 2nd # with the inner & (the map)
The answer in this example should by {2}
(of course, the statement as written above does not do the job)

Can Mathematica distinguish these #'s?

Thanks in advance,
Dave Snead

• Follow-Ups:
  • Re: Distinquishing #'s in nested pure functions
    • From: Murray Eisenberg <murray@math.umass.edu>
  • Re: Distinquishing #'s in nested pure functions
    • From: Sseziwa Mukasa <mukasa@gmail.com>

• References:
  • NonlinearModelFit and Complex Data
    • From: Maria <rouelli@gmail.com>