2. Structuring Search Problems

To formulate a problem we create a formal model of the problem, $\Sigma =(S,A,\gamma )$. It includes:

• Initial State, $S$
• Set of Actions, $A$
• State-Transition Function, $\gamma (s,a)\to s^{\prime }$ where $s\in S$, $a\in A$
• Goal State
• Cost Function

A solution to a problem is an action sequence that leads from the initial state to the goal state. An optional solution is the solution with the lowest cost function.