Exemplo n.º 1
0
def extract_axiom_plan(task, goals, negative_from_name, static_state=set()):
    import pddl_to_prolog
    import build_model
    import instantiate
    # TODO: only reinstantiate the negative axioms
    axioms_from_name = get_derived_predicates(task.axioms)
    derived_goals = {l for l in goals if l.predicate in axioms_from_name}
    axiom_from_action = get_necessary_axioms(derived_goals, task.axioms, negative_from_name)
    if not axiom_from_action:
        return []
    conditions_from_predicate = defaultdict(set)
    for axiom, mapping in axiom_from_action.values():
        for literal in get_literals(axiom.condition):
            conditions_from_predicate[literal.predicate].add(literal.rename_variables(mapping))

    original_init = task.init
    original_actions = task.actions
    original_axioms = task.axioms
    # TODO: retrieve initial state based on if helpful
    task.init = {atom for atom in task.init if is_useful_atom(atom, conditions_from_predicate)}
    # TODO: store map from predicate to atom
    task.actions = axiom_from_action.keys()
    task.axioms = []
    # TODO: maybe it would just be better to drop the negative throughout this process until this end
    with Verbose(False):
        model = build_model.compute_model(pddl_to_prolog.translate(task))  # Changes based on init
    task.actions = original_actions
    task.axioms = original_axioms

    opt_facts = instantiate.get_fluent_facts(task, model) | (task.init - static_state)
    mock_fluent = MockSet(lambda item: (item.predicate in negative_from_name) or (item in opt_facts))
    instantiated_axioms = instantiate_necessary_axioms(model, static_state, mock_fluent, axiom_from_action)
    axiom_plan = extraction_helper(task.init, instantiated_axioms, derived_goals, negative_from_name)
    task.init = original_init
    return axiom_plan
Exemplo n.º 2
0
def extract_axiom_plan(task, action_instance, negative_from_name, static_state=set()):
    import pddl_to_prolog
    import build_model
    import axiom_rules
    import instantiate

    axioms_from_name = get_derived_predicates(task.axioms)
    derived_preconditions = {l for l in action_instance.precondition if l.predicate in axioms_from_name}
    nonderived_preconditions = {l for l in action_instance.precondition if l not in derived_preconditions}
    if not conditions_hold(task.init, nonderived_preconditions):
        return None

    axiom_from_action = get_necessary_axioms(action_instance, task.axioms, negative_from_name)
    if not axiom_from_action:
        return []
    conditions_from_predicate = defaultdict(set)
    for axiom, mapping in axiom_from_action.values():
        for literal in get_literals(axiom.condition):
            conditions_from_predicate[literal.predicate].add(literal.rename_variables(mapping))

    original_init = task.init
    original_actions = task.actions
    original_axioms = task.axioms
    task.init = {atom for atom in task.init if is_useful_atom(atom, conditions_from_predicate)}
    # TODO: store map from predicate to atom
    task.actions = axiom_from_action.keys()
    task.axioms = []
    # TODO: maybe it would just be better to drop the negative throughout this process until this end
    with Verbose(False):
        model = build_model.compute_model(pddl_to_prolog.translate(task))  # Changes based on init
    task.actions = original_actions
    task.axioms = original_axioms

    opt_facts = instantiate.get_fluent_facts(task, model) | (task.init - static_state)
    mock_fluent = MockSet(lambda item: (item.predicate in negative_from_name) or (item in opt_facts))
    instantiated_axioms = instantiate_necessary_axioms(model, static_state, mock_fluent, axiom_from_action)

    goal_list = []
    with Verbose(False):
        helpful_axioms, axiom_init, _ = axiom_rules.handle_axioms(
            [action_instance], instantiated_axioms, goal_list)
    axiom_init = set(axiom_init)
    axiom_effects = {axiom.effect for axiom in helpful_axioms}
    #assert len(axiom_effects) == len(axiom_init)
    for pre in list(derived_preconditions) + list(axiom_effects):
        if (pre not in axiom_init) and (pre.negate() not in axiom_init):
            axiom_init.add(pre.positive().negate())
    axiom_from_atom = get_achieving_axioms(task.init | axiom_init, helpful_axioms, negative_from_name)
    axiom_plan = []  # Could always add all conditions
    success = extract_axioms(axiom_from_atom, derived_preconditions, axiom_plan, negative_from_name)
    task.init = original_init
    #if not success:
    #    return None
    return axiom_plan
Exemplo n.º 3
0
def recover_stream_plan(evaluations,
                        goal_expression,
                        domain,
                        stream_results,
                        action_plan,
                        negative,
                        unit_costs,
                        optimize=True):
    import pddl_to_prolog
    import build_model
    import pddl
    import axiom_rules
    import instantiate
    # Universally quantified conditions are converted into negative axioms
    # Existentially quantified conditions are made additional preconditions
    # Universally quantified effects are instantiated by doing the cartesian produce of types (slow)
    # Added effects cancel out removed effects

    opt_evaluations = evaluations_from_stream_plan(evaluations, stream_results)
    opt_task = task_from_domain_problem(
        domain,
        get_problem(opt_evaluations, goal_expression, domain, unit_costs))
    real_task = task_from_domain_problem(
        domain, get_problem(evaluations, goal_expression, domain, unit_costs))
    function_assignments = {
        fact.fluent: fact.expression
        for fact in opt_task.init  # init_facts
        if isinstance(fact, pddl.f_expression.FunctionAssignment)
    }
    type_to_objects = instantiate.get_objects_by_type(opt_task.objects,
                                                      opt_task.types)
    results_from_head = get_results_from_head(opt_evaluations)

    action_instances = []
    for name, args in action_plan:  # TODO: negative atoms in actions
        candidates = []
        for action in opt_task.actions:
            if action.name != name:
                continue
            if len(action.parameters) != len(args):
                raise NotImplementedError(
                    'Existential quantifiers are not currently '
                    'supported in preconditions: {}'.format(name))
            variable_mapping = {
                p.name: a
                for p, a in zip(action.parameters, args)
            }
            instance = action.instantiate(variable_mapping, set(), MockSet(),
                                          type_to_objects,
                                          opt_task.use_min_cost_metric,
                                          function_assignments)
            assert (instance is not None)
            candidates.append(((action, args), instance))
        if not candidates:
            raise RuntimeError(
                'Could not find an applicable action {}'.format(name))
        action_instances.append(candidates)
    action_instances.append([(None, get_goal_instance(opt_task.goal))])

    axioms_from_name = get_derived_predicates(opt_task.axioms)
    negative_from_name = {n.name: n for n in negative}
    opt_task.actions = []
    opt_state = set(opt_task.init)
    real_state = set(real_task.init)
    preimage_plan = []
    function_plan = set()
    for layer in action_instances:
        for pair, instance in layer:
            nonderived_preconditions = [
                l for l in instance.precondition
                if l.predicate not in axioms_from_name
            ]
            #nonderived_preconditions = instance.precondition
            if not conditions_hold(opt_state, nonderived_preconditions):
                continue
            opt_task.init = opt_state
            original_axioms = opt_task.axioms
            axiom_from_action = get_necessary_axioms(instance, original_axioms,
                                                     negative_from_name)
            opt_task.axioms = []
            opt_task.actions = axiom_from_action.keys()
            # TODO: maybe it would just be better to drop the negative throughout this process until this end
            with Verbose(False):
                model = build_model.compute_model(
                    pddl_to_prolog.translate(
                        opt_task))  # Changes based on init
            opt_task.axioms = original_axioms

            opt_facts = instantiate.get_fluent_facts(
                opt_task, model) | (opt_state - real_state)
            mock_fluent = MockSet(lambda item: (
                item.predicate in negative_from_name) or (item in opt_facts))
            instantiated_axioms = instantiate_necessary_axioms(
                model, real_state, mock_fluent, axiom_from_action)
            with Verbose(False):
                helpful_axioms, axiom_init, _ = axiom_rules.handle_axioms(
                    [instance], instantiated_axioms, [])
            axiom_from_atom = get_achieving_axioms(opt_state, helpful_axioms,
                                                   axiom_init,
                                                   negative_from_name)
            axiom_plan = []  # Could always add all conditions
            extract_axioms(axiom_from_atom, instance.precondition, axiom_plan)
            # TODO: test if no derived solution

            # TODO: compute required stream facts in a forward way and allow opt facts that are already known required
            for effects in [instance.add_effects, instance.del_effects]:
                for i, (conditions, effect) in enumerate(effects[::-1]):
                    if any(c.predicate in axioms_from_name
                           for c in conditions):
                        raise NotImplementedError(
                            'Conditional effects cannot currently involve derived predicates'
                        )
                    if conditions_hold(real_state, conditions):
                        # Holds in real state
                        effects[i] = ([], effect)
                    elif not conditions_hold(opt_state, conditions):
                        # Does not hold in optimistic state
                        effects.pop(i)
                    else:
                        # TODO: handle more general case where can choose to achieve particular conditional effects
                        raise NotImplementedError(
                            'Conditional effects cannot currently involve certified predicates'
                        )
            #if any(conditions for conditions, _ in instance.add_effects + instance.del_effects):
            #    raise NotImplementedError('Conditional effects are not currently supported: {}'.format(instance.name))

            # TODO: add axiom init to reset state?
            apply_action(opt_state, instance)
            apply_action(real_state, instance)
            preimage_plan.extend(axiom_plan + [instance])
            if not unit_costs and (pair is not None):
                function_plan.update(
                    extract_function_results(results_from_head, *pair))
            break
        else:
            raise RuntimeError('No action instances are applicable')

    preimage = plan_preimage(preimage_plan, set())
    preimage -= set(real_task.init)
    negative_preimage = set(
        filter(lambda a: a.predicate in negative_from_name, preimage))
    preimage -= negative_preimage
    # visualize_constraints(map(fact_from_fd, preimage))
    # TODO: prune with rules
    # TODO: linearization that takes into account satisfied goals at each level
    # TODO: can optimize for all streams & axioms all at once

    for literal in negative_preimage:
        negative = negative_from_name[literal.predicate]
        instance = negative.get_instance(map(obj_from_pddl, literal.args))
        value = not literal.negated
        if instance.enumerated:
            assert (instance.value == value)
        else:
            function_plan.add(
                PredicateResult(instance, value, opt_index=instance.opt_index))

    node_from_atom = get_achieving_streams(evaluations, stream_results)
    preimage_facts = list(
        map(fact_from_fd, filter(lambda l: not l.negated, preimage)))
    stream_plan = []
    extract_stream_plan(node_from_atom, preimage_facts, stream_plan)
    if not optimize:  # TODO: detect this based on unique or not
        return stream_plan + list(function_plan)

    # TODO: search in space of partially ordered plans
    # TODO: local optimization - remove one and see if feasible

    reschedule_problem = get_problem(evaluations,
                                     And(*preimage_facts),
                                     domain,
                                     unit_costs=True)
    reschedule_task = task_from_domain_problem(domain, reschedule_problem)
    reschedule_task.actions, stream_result_from_name = get_stream_actions(
        stream_results)
    new_plan, _ = solve_from_task(reschedule_task,
                                  planner='max-astar',
                                  debug=False)
    # TODO: investigate admissible heuristics
    if new_plan is None:
        return stream_plan + list(function_plan)

    new_stream_plan = [stream_result_from_name[name] for name, _ in new_plan]
    return new_stream_plan + list(function_plan)