st: how to flag up obs that are the reverse of other obs?

["Ada Ma" <Pelikan_4001@hotmail.com>]

I want to know how to drop some observations.  For example I have the
following data, the numbers are identifiers:

Original        Fake
1                    23
14                   235
35                    90
45                    87
87                    45

Now the 4th and 5th pairs are the exact opposite of one another.  I want to
drop the 5th observation, but I don't know I can use the data to flag up
such observations so that I can drop it.  Could someone show me the light?

Many thanks in advance.

Yours,
Ada



Ada Ma
Department of Economics
University of Aberdeen, Scotland
Pelikan_4001@hotmail.com
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