Behaviors
Given an input sequence
x = (x(0), x(1), x(2), ... ),
if a state machine can produce the output sequence
y = (y(0), y(1), y(2), ... ),
then (x, y) is said to be a behavior of the state machine. The set of all behaviors of a state machine obviously satisfies
Behaviors ⊂ InputSignals × OutputSignals
where
InputSignals = [Naturals0 → Inputs]
OutputSignals = [Naturals0 → Outputs]