Re: LP/MIP solver interface lib(eplex)

Hi Mauro,

>I use version 5.5 of ECLiPSe and I need to import the eplex library, but from 
>some week it doesn't work anymore; it shows the error message:
>XPRESS error (probably licencing problem)

When reporting a problem, it would be very helpful if you include as much
information as possible. Information that would help us to pinpoint you
problem include:

1) Which version of Xpress you are trying to use.
2) What platform you are running ECLiPSe on.
3) All the output ECLiPSe prints when you get the error.

Without such information, it is difficult to give you precise help.

However, you message suggest that you had a working Xpress with eplex
previously. If this is the case, the most likely reason is because
your Xpress license have recently expired. *IF* this is the case, you
should have seen a message from Xpress telling you this, e.g. when I try to
load Xpress 13, I get:

[eclipse 2]: lib(eplex).
range.eco  loaded traceable 0 bytes in 0.01 seconds
linearize.eco loaded traceable 0 bytes in 0.01 seconds
hash.eco   loaded traceable 0 bytes in 0.00 seconds
var_name.eco loaded traceable 0 bytes in 0.01 seconds
constraint_pools.eco loaded traceable 0 bytes in 0.00 seconds
loading XPRESS 1326icp ... done
This XPRESS license has expired

Release 13 is not authorized. Contact Dash for a commercial license
XPRESS error (probably licencing problem)

Did you get these extra lines of messages? 

Dash also forwarded your e-mail to them about this problem to me, where you
said: 

>I'm a student and I use the Xpress-MP Student Edition.

Which `student edition' of Xpress are you trying to use? ECLiPSe 5.5 is
quite old, and you cannot use the most recent versions of Xpress with it.

[and in addition, recent version the student edition of Xpress requires a
different Xpress library from the standard version, and we don't support these
student editions in more recent versions of ECLiPSe]

Cheers,

Kish Shen