Turing Machine BY: ARAM RAFEQ GROUP –A-
Jul 16, 2015
Turing MachineBY: ARAM RAFEQ GROUP –A-
What is Turing Machine
So what is Turing Machine ?
Is it some physical machine ?
Or some sort of imaginary machine ?
The answer
The answer is it’s both logical and physical device!!!
The Turing machine can be logical device then we convert it
to physical device one example we can create a TM that
reverse a string
A physical Turing Machine
Here I will show you an actual Turing machine
Lets get started
Every machine have an input and an output between the input and output
there is process
The input to any TM is just a String
The Output is also a string
The process here we will create it according to our need later we will see
how to design it
Our goal ?
Our goal in designing any Turing machine is to implement our idea in term of states and
transitions so we need to know about our recourses but before that
Transitions
State State
Our recourses
The only recourse that we have is long tape its exactly like an array
But how we can use this tape ?
For every game we have set of rules here also just like a game
I tells you , you can use this tape so design this for me
The rules
Here is what you can do with this tape
1- you can read cell by cell
2- you can change the content of the cell
3- you can move to the right or to the left
4- you can use as much as you want from the tape its like infinite storage store
as elements as you wish
You cannot do this
You can not do this things in our game
1- you cannot jump form a cell to a far cell just cells next to each other
2- we will give you set of thing you can use them only as input to our
machine
Structure of Turing Machine
Read/Write headWe can read or write any symbol that we like
The Tape
Finite state
control
Formal Definition of Turing Machine
TM= {Q,┌,b, ∑,δ ,𝑞0,𝐹}
Q : is a finite, non-empty set of states
┌ : is a finite, non-empty set of the tape alphabet/symbols
B : is the blank symbol (the only symbol allowed to occur on the tape infinitely often at
any step during the computation)
∑ : is the set of input symbols
𝑞0 : is the initial state
F : is the set of final or accepting states.δ : called the transition function, where L is left shift, R is right shift.
Some Examples
Ex1 : Design a Turing Machine that multiply a binary number by 2
Solution :
Some Examples
Ex2 : Design a Turing Machine that 2’s complement for a binary
number
Solution :
Some Examples
Ex3 : Design a Turing Machine that accepts word form this
language L (G) = { 1𝑛0𝑧 / n≥1, z ≥0}
Solution :
Thanks for your Attention