Re: [Help-glpk] Empty Sets

[Andrew Makhorin]

> when I try to specify an empty set in the data file I cannot make it 
> work, though it is working in the above version:
> 
> set S := {}; /* In the data file */
> 
> obtaining: syntax error in set data block
> 
> the other way round does not work either, i.e., defining an empty set in 
> the model and trying to override this in the data file.
> 
> Whatever suggestion is appreciated.
> 

You can declare the set as follows:

set S, default {};

In this case, if no value is given for S in the data section, the
default value (an empty set) will be used. For more details please see
the language reference.