[gecode-users] cumulatives constraint

[David Rijsman]

I have a question on the cumulatives constraint. I have a simple case
where I expect more pruning on the start variable and I just want to
make sure if my expectation is correct (before digging into the paper
and implementation):

The case is two tasks both assigned to the same single machine, first
task starts at 0 and ends at 20, second tasks has a duration of 20 can
initially start between 0 and 40 and end between 20 and 60. The
machine has limit 1 and the amount used of the resource should be less
(at_most=true) than the limit and the height of both tasks is 1.

I would expect the start of the second variable to be pruned from
[0,40] to [20,40] but what we see (when we run the attached file) is a
search on the start variable failing 20 times (trying start
0,1,2,...19) before finding the first solution. Obviously I expect the
first decision to be a solution. Am I expecting to much propagation on
a task without compulsory part?

David Rijsman
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