> How can I undo the declaration of variables, respectively, constraints,
> if they becom superfluous? I don't want to override them, I want to
> delete them and free related memory! Anyone an idea?

> Thanks a lot!!!

> -------------------

> This thread replaces the undermentioned:

> "Hi! My optimization model is extended stepwise, that is, it is set-up
> and solved for a specific planning horizon and extended afterwards to
> cover more periods. This is done to simulate a rolling horizon
> environment. Therefore, in each simultion run the optimization model is
> extended with new constraints and variables. Only in under special
> circumstance some already inialized constraints in variable are
> superfluous. I would like to delete these not needed constraints and
> variables, because for large simulation instances the model exceeds the
> available RAM of my computer and Xpress terminates. There are a lot of
> not needed constraints, because preprocessing always reduces the
> problem size strongly.

> How do I delete constraints and variables? Does a corresponding
> function to "create" exist? Or could I use "sethidden"? I could image
> that the latter doesn't help to reduce memory usage...

>  Thanks a lot!"