The simplest kind of agent is the simple reflex agent. These agents select actions on the basis of the current percept, ignoring the rest of the percept history. For example, the vacuum agent whose agent function is a simple reflex agent, because its decision is based only on the current location and on whether that location contains dirt.

An agent program for this agent is shown in Figure.

Notice that the vacuum agent program is very small indeed compared to the corresponding table.

The most obvious reduction comes from ignoring the percept history, which cuts down the number of possibilities from 4T to just 4. A further, small reduction comes from the fact that when the current square is dirty, the action does not depend on the location.

Simple reflex behaviors occur even in more complex environments. Imagine yourselves the driver of the automated taxi. If the car in front brakes and its brake lights come on, then you should notice this and initiate braking. In other words, some processing is done on the visual input to establish the condition we call “The car in front is braking.”