Temporal problem support (via LPG-td?)

[nvitucci]

User Story

As a planning user, I would like to solve a temporal problem such as the one described here.

Acceptance Criteria

• Have at least one supported planner solve it.

Additional Material

The problem has the following features, and apparently there is no planner supporting all of them:

PROBLEM_CLASS: ['ACTION_BASED']
TIME: ['CONTINUOUS_TIME']
EXPRESSION_DURATION: ['STATIC_FLUENTS_IN_DURATIONS', 'REAL_TYPE_DURATIONS']
TYPING: ['FLAT_TYPING']
QUALITY_METRICS: ['MAKESPAN']
INITIAL_STATE: ['UNDEFINED_INITIAL_NUMERIC']

I used LPG-td manually to solve it, but LPG-td does not seem to be supported in unified-planning (or up-lpg).

I've created an issue in the up-lpg repo too. Feel free to close it if it's not the right place to raise it.

[nvitucci]

As I added in the up-lpg issue, if I manually run the LPG executable from the virtual environment with the same domain and problem files, a solution is actually found. So it does not seem an issue with the planner itself.

[nvitucci]

One thing I noticed is that in the docs you mention that LPG supports makespan, but apparently the engine is not configured this way.

As a test, if I add the following lines to lpg_planner.py, the LPG solver runs (although with a different error):

supported_kind.set_quality_metrics('MAKESPAN')
supported_kind.set_initial_state('UNDEFINED_INITIAL_NUMERIC')

[alvalentini]

Hi @nvitucci, thanks for opening the issue.

LPG should in principle already support both MAKESPAN and UNDEFINED_INITIAL_NUMERIC, so up-lpg likely needs to be updated to properly handle them.

Adding these features to supported_kind (as you tried) is definitely required, but there are probably additional changes needed in the integration.

@serivan could you take a look?

[nvitucci]

Thanks, Alessandro. Indeed, once I get the engine to run, there is a different issue related to parsing the resulting plan. If I replace the hardcoded -n 1 parameter with -quality in the CLI command, I get the correct result.
It would be nice if, besides being fixed, this could be made configurable.

As a side question: does it make sense for UNDEFINED_INITIAL_NUMERIC to actually be set in the engine itself?