Turing Machine of equal a and b in theory of automata

By: Prof. Fazal Rehman Shamil
Last modified on January 25th, 2021

Turing Machine of equal a’s and b’s:

Suppose we want to design a Turing Machine for the language of anbn where a=b.


If machine reads anyone a from the input tape, then machine write X and if machine reads any b then machine write y;

a = X

b = Y

Purpose to make every a as X and to every b as Y is only to match one a with one b. This is the way to the bound equal number of a’s and b’s.

Accepted strings:

Such kind of strings should be accepted by Turing Machine.

e.g, ab, aabb, aaabbb,…..etc.

Rejected strings:

Such kind of strings should be rejected by Turing Machine.

e.g, abb, aab, aaabb,…..etc.

Turing machine in toc
Figure: Turing machine of all equal length strings

Read More Examples of Turing Machine

  1. Turing Machine to copy a string: with animations
  2. Turing Machine of numbers divisible by 3: with animations
  3. Turing machine for anbncn: with animations
  4. Turing machine of two equal binary strings: with animations

  5. Turing Machine to Accepts palindromes: with animations

  6. Turing machine for a’s followed by b’s then c’s where the number of a’s multiplied by the number of b’s and equals to the number of c’s: with animations

  7. Turing machine to Add two binary numbers: with animations

  8. Turing machine to  Multiply two unary numbers: with animations
  9. Turing machine to Multiply two binary numbers: with animations
  10. Turing Machine for the complement of a string
  11. Turing Machine for the language of anbn where a=b.
  12. Turing Machine for a is less than b, ambn where a=b or m=n.
  13. Turing machine for the language of all those string in which a is less than b


Prof. Fazal Rehman Shamil