Time To find the shortest plan, look for a plan at timestep 1, then 2,etc c.222003 16.410/13, Programming SATPlan, Greg Sullivan
Time • To find the shortest plan, look for a plan at timestep 1, then 2, etc. Oct. 22, 2003 16.410/13, Programming SATPlan, Greg Sullivan 6
Encoding Actions (action(fly(p plane)(from airport)(to airport) ((plane-at p from) ((not (plane-at p from)(plane-at p to) Base encoding on successor state axioms presented in r&n ch ch 7 for the situation calculus 16.410/13, Programming SATPlan, Greg Sullivan
Encoding Actions (action (fly (p plane) (from airport) (to airport)) ((plane-at p from)) ((not (plane-at p from)) (plane-at p to))) • Base encoding on successor state axioms presented in R&N ch. 7, for the situation calculus. Oct. 22, 2003 16.410/13, Programming SATPlan, Greg Sullivan 7
Actions Successor state axioms in words P is true at time t+1 if either of the following is true 1. For some action that establishes p(has p as a postcondition) a. all of P's preconditions are satisfied at time t b. the action was taken at time t 2. Or, p was true at time t, and whatever action that was taken at time t doesn ' t undo p c.222003 16.410/13, Programming SATPlan, Greg Su
Actions Successor State axioms in words: P is true at time t+1 if either of the following is true: 1. For some action that establishes P (has P as a postcondition), a. all of P’s preconditions are satisfied at time t b. The action was taken at time t. 2. Or, P was true at time t, and whatever action that was taken at time t doesn’t undo P. Oct. 22, 2003 16.410/13, Programming SATPlan, Greg Sullivan 8