This document defines and describes a Mealy machine, which is a type of finite state machine where the output depends on both the present state and present input. It specifies that a Mealy machine can be represented as a 6-tuple including the set of states, input symbols, output symbols, state transition function, output function, and initial state. An example Mealy machine is provided showing the next state, output, and transition based on the current state and input.

1. Mealy Machine
Prof.Neeraj Bhargava
Abhishek Kumar
Department of Computer Science
School of Engineering & System Sciences,
MDS, University Ajmer, Rajasthan, India

2. Contents:-
• Mealy Machine

3. Mealy Machine:-
 A Mealy Machine is an FSM whose output depends on
the present state as well as the present input.
 It can be described by a 6 tuple (Q, ∑, O, δ, X, q0) where
 Q is a finite set of states.
 ∑ is a finite set of symbols called the input alphabet.
 O is a finite set of symbols called the output alphabet.
 δ is the input transition function where δ: Q × ∑ → Q
 X is the output transition function where X: Q × ∑ →
O
 q0 is the initial state from where any input is processed
(q0 ∈ Q).

4. Present
state
Next state
input = 0 input = 1
State Output State Output
→ a b x1 c x1
b b x d x3
c d x3 c x1
d d x3 d x2