title: How to prove two algorithms are equivalent?
body: <p>I have written two widely different algorithms which are supposed to give same output for same input.But how do I prove they are equivalent? 
  Is it even possible? I know that there is no general algorithm to prove equality of two algorithms. But is it possible if two algorithms are given? '
  I would appreciate if you give links to some books or Pdf related to this even if you don't give the steps.
  Thanks in advance.</p>