We divide the cooking time into discrete steps defined by time_increment.
For each timestep, we define <dish>_in_<time> and <dish>_out_<time> for
each dish. Keeping these separate allows us to apply an ovening-opening penalty
in the objective without breaking linearity.
We apply simple physical constraints ensuring a dish's in-ness == 0 or 1 and the oven occupancy does not exceed the oven size. We also constrain each dish's cooking time to be met within 5 minutes.
Each dish is scored on its hotness, multiplied by its serve_hot_weight. This
weight can take any real value, though it seems the solver has trouble with
floating points. Set it to zero to allow serving cold. A dish is considered hot
if it was in the oven for one of the last four steps of cooking (TODO).
The objective is penalised by the number of oven openings, multiplied by
the oven_opening_weight. Currently this counts each put_in and take_out
separately, even if they are simultaneous. Either way, it leads to some
desireable properties -- dishes are not repeatedly taken in and out without
good reason, and dishes are likely to be put in later and taken out at the end.