Figure 1. Examples of an instance of control software in the form of a finite-state machine (A) and a behavior tree (B).
The finite-state machine contains two states (represented by circles), with associated behaviors B1 and B2, and a total of three transitions (represented by arrows), with associated conditions C1, C2, and C3 (represented through diamonds).The behavior tree contains a sequence* node (→∗) as the top-level node. Underneath it are two selector nodes (?). Each of the selector nodes has two children: an action node (represented as a circle), with associated behaviors B1 and B2 respectively, and a condition node (represented as a diamond), with associated conditions C1 and C2 respectively.