- ...Weld
- We thank Denise Draper, Steve Hanks,
Terrance Goan, Nick Kushmerick, Neal Lesh, Rich Segal, and Mike
Williamson for helpful discussions. This research was funded in part
by Office of Naval Research Grants 90-J-1904 and 92-J-1946, and by
National Science Foundation Grants IRI-8957302, IRI-9211045, and
IRI-9357772. Golden is supported in part by a UniForum Research
Award.
- ...planner
- XII stands for ``eXecution and Incomplete Information.''
- ...,
- Our thanks to Anthony
Barrett and Daniel Weld at the University of Washington for providing us
with the code for the UCPOP planner.
- ...planners.
- In fact, our agent
relaxes this assumption by associating expiration times with beliefs
in
and 
and by recovering from errors that result from
incorrect information. However, a discussion of this mechanism is
beyond the scope of this paper.
- ...LCW.
- XII operator schemata explicitly distinguish between
causal effects (that change the state of the external world) and
observational effects (that only change the state of XII 's model) as
explained in [4].
- ...details.
- Note also that the classical universal base mechanism
requires that a type's universe be static and finite. XII correctly
handles dynamic universes. Furthermore, XII's policy of linking to
effects handles infinite universes, but this is not of
practical import.
- ...confrontation.
- The first two techniques order the threatening
action before the link's producer or after its consumer. Confrontation
works when the threatening effect is conditional; the link is protected
by subgoaling on the negation of the threat's
antecedent [14].
- ...Q(foo)R(foo)
- Note the difference
between shrinking and protecting a link
(section 3.1). Unlike the link case, shrinking does
not have a disjunct corresponding to S(foo).
- ...redundant.
- We cannot simply associate
exactly one sensory action with each goal, a priori, because the
agent may fail to satisfy that action's preconditions - in which
case trying a different sensory action is warranted.
- ...set.
- Since XII can
subsequently lose LCW due to information loss or domain growth
(Section 3.2), it has to record this pruning decision and
recompute the options for
once
LCW(G) is lost. Doing this in an efficient but sound manner is
actually quite complex - see [8] for the details.