STRIPS Task

A quadruple $\Pi :=⟨P,A,I,G⟩$ where

• $P$ is a finite set of facts (propositions)
• $A$ is a finite set of actions
  • each action is a tripe of subsets of the facts
    • Precondition
    • Add List (true after action is done)
    • Delete List (false after action is done)
    • where the intersection of the add and delete list is empty
• $I\subseteq P$ is the initital state
• $G\subseteq P$ is the goal state

We can give actions a name (string) and assume that every action has a cost of 1.

We try to generate a Search Problem from a STRIPS task.

Search Problem:

• states are conjunctions of facts (so Potenzmenge)
• actions are the same
• Transition Model:
  • applying action to state is only possible when actions Precondition is met → action is applicable
  • then apply-function of transition model adds the Add List to the state and deletes the Delete List from the state
• goal states is the same (goal state is in the current state)
• initial states is the same
• solutions: paths from initital state to goal state
  • for example: Iterative Deepening search on state space

Problem: The states in the Search Problem also include parts that are not reachable in the Planning Task.

Blocks World Miconic-10