The document describes common search techniques used to solve problems. It provides a general search algorithm that initializes a set called OPEN, selects and removes states from OPEN, and expands the successors of selected states by applying actions/operations until a goal state is found. It then contrasts depth first search, which uses a stack for OPEN, and breadth first search, which uses a queue for OPEN.

2. Searching
Techniques

3. Search: General Information

4. General Algorithm of a Search
1. INITIALIZE : set OPEN = {s}
2. FAIL: if OPEN = { }, Terminate with failure
3. SELECT: Select a state n from OPEN
4. TERMINATE: if n ϵ G, terminate with success
otherwise
5. EXPAND: Generate the
successors/descendants of n using A
(operation/actions)
and insert in OPEN
6. LOOP: Go to step 2

5. Depth First Search – OPEN as STACK
1
2 3 4
6 5
7
9 8

6. •

7. Breadth First Search – OPEN as QUEUE
1
2 3 4
6 5
7
9 8