fix skipping over values in constraint implementation

[matzemathics]

No description provided.

[matzemathics]

@aannleax I'm unsure whether there could be a similar problem in line 380.
https://github.com/knowsys/nemo/pull/380/files#diff-49d351e3f72e81729798365883f856f6de2870555aeac5fd421d34a3cfca0591L308

[aannleax]

I'm not sure what we want actually. For something like R(?z) :- A(?x, ?y), ?z = ?x / ?y, we want to skip all results with ?y = 0. For constraints R(?x, ?y) :- A(?x, ?y), ?x / ?y > 10 I'm not sure but I think we also want to skip the rows (so treat it as a if the constraint was not satisfied).

To do this the function check_condition should probably just have the return type bool and go into State::After if there is an undefined expression.

satisfy_lower_bound should probably return nothing and loop while tree.evaluate returns None

check_upper_bound could stay as before, but the code that uses it should loop until it returns either true or false

[aannleax]

I can also do the fixes, if you want

[matzemathics]

I can also do the fixes, if you want

Yes feel free to pick this up, I'm not sure I understand all your remarks.

Skipping rows, where division by zero occurs is expected for me, the sole problem is that it also skipped non-divide-by-zero-rows that are in the same group as a divide-by-zero-row, which seems unexpected to me.

[aannleax]

Ok, I think it makes sense now

[matzemathics]

Ok, I think it makes sense now

Nice, I will try and add some more test cases then we can get this merged

[matzemathics]

@aannleax @mmarx anything still missing? otherwise I'd suggest we get this merged.