Heya! Very nice and congratulations on the front page :) On (2) that's the great part about solvers, is that they're essentially quite incredible black boxes.

Heya! Very nice and congratulations on the front page :) On (2) that's the great part about solvers, is that they're essentially quite incredible black boxes. Most people who actually do optimization theory also don't really know how they work. (My money is on black magic for a number of cases.) Kidding aside, writing one is always informative and interesting (and, with languages like Julia, surprisingly not complicated). 3) My suspicion is that matrix notation would actually improve the end result quite a bit. A lot of the constraints you've written down have very common structure (e.g., the total weight constraint can be written as y = X'g, where m is the vector of weights, or the required assignment constraint, X1 = 1, where 1 is the all-ones vector). Writing this out and the corresponding descriptions next to it would make it much easier to parse. E.g., for the above cases min tr(CX) + c'y s.t. X1 = 1 (all items need to be shipped) X'g = y (y is the total weight on each ULD) etc. Congrats again on the front page and the article!