data-structures

Definition

And-Or Tree

An and-or tree is a search tree used to model problems involving choices, decompositions, or uncertainty (like nondeterministic action), utilising two alternative types of nodes:

  1. OR nodes: OR nodes represent points where selecting any one successful action or path is sufficient.
  2. AND nodes: AND nodes represent points where all resulting sub-problems or outcomes must be successfully handled to achieve the overall goal.

Usage

This structure is often used in planning or problem-solving where an agent must make decisions (OR) and handle various consequences or requirements (AND).