Re: lp/mip preprocessor api

> This is true, however after step L4 in your suggested API:
> Q = glp_npp_build_prob(npp, ...);
> any subsequent modifications to Q are not reflected in the PP
> workspace. My suggestion is to allow calling glp_npp_load_prob() with
> this modified Q (with changed bounds or added rows) to update the
> workspace before further preprocessing passes. 

There is no need (and technically it'd be difficult) to load Q back into
the PP wksp. It would be sufficient to provide some specific
preprocessor routines that allows, for example, fixing a column or add a
row to the current instance residing in the workspace.