The ideas of HSP can be used in the context of Functional Strips (see
(BLG97) for related results). The key point is the automatic extraction of the heuristic from
Functional Strips encodings. We have been explor ing a number of ways for doing this, but
coming up with an efficient im plementation that can be competitive with HSP on similar
problems has been difficult. The problem is that the effect of postconditions f (t) := w in
Functional Strips is state dependent when the terms t or w involve
fluent symbols. An alternative that we are currently exploring for com puting the heuristic is
to translate this context-dependent updates into equivalent sets of conditional but
context-independent updates of the form C ---+ f(t') := w1 , where t1 and w1 have
no fluent symbols and C = (t = t') 1 (w = w').