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AMPL > >Sets and Indexing > >Why doesn’t AMPL interpret the expression T..1 as I expect?

In general, AMPL interprets a..b as {a, a+1, a+2, ..., b-1, b}. Thus when T is greater than one, T..1 is an empty set. To specify the ordered set that goes from T down to 1, write T..1 by -1.

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