[SCIP] What SCIP does when objective function equal to zero

[Vladimir V. Voloshinov]

Dear SCIP team,
Merry Christmas! and Happy New Year!

But still we have a question: how SCIP (and ParaSCIP) treat the problem
where objective function is absent, i.e. equal to zero?
That is the problem  is actually a satisfiability problem, the search of a
feasible solution for a set of constraints given.

My colleagues ask me to run ParaSCIP with some rather hard problem with
binary variables of the above type, which took about 170 CPU*hour to be
solved on rather power cluster.
In attempt to reduce solving time I have recommended them to reformulate
the problem, i.e. to bring some constraints to the criterium via penalty
function... But as a result we got much more hard problem with dozens more
solving time (I even had to kill ParaSCIP after 1000 CPU*hours of
calculating with gap around 20%).
The same effect was for variants of the same problems of smaller dimensions
(solved by SCIP): converting some constraints to the penalty made the
problem much more hader (for SCIP).

Can you tell a few words about SCIP's approach to the problem with constant
goal function? May be there are some papers on the subject?

Sincerely yours,
Vladimir.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listserv.zib.de/pipermail/scip/attachments/20191228/e3094a58/attachment.html>