Forward state-space planning
= Forward state-space planning
Expand a concrete state by applying every action whose <preconditions> hold, and search the resulting state <graph> for a goal. For <STRIPS>, the successor is $(S\setminus\operatorname{Del}(a))\cup\operatorname{Add}(a)$. A valid expansion checks the complete <precondition> set, including resource markers such as an empty hand, rather than only an action's geometric destination.