[Help-glpk] New set functions

[Nilo Cesar Teixeira]

Hi all,

In my previous question (regarding printf and if), I thought about this _expression_ which is invalid in current version of MathProg:

printf "%30s", (if card({name in I : H[name] = 1}) = 0 then '*' else XXXX);

My point is, I would like XXXX to be an _expression_ which returns ONE element of a set. In this case, the value of 'name' for which H[name] = 1.

I thought about these 2 functions which could be useful:

1. first({name in I : H[name] = 1}), would return value of name; last() would be good too;
2. member {name in I : H[name] = 1} (i), would return the ith member of set.

So, member {name in I : H[name] = 1} (1) would return value of name too;

To really be effective, this should work with unsubscripted sets to, like set I := A NO THER MEM BER;

Suppose H[A] = 1, so the above functions return A.

What do you think ? Thank you.

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Nilo Cesar Teixeira
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