In mathematics, a fixed point is a value of a function that maps to its self. In other words, x is a fixed point of a function f if f(x) = x.

According to Kleene’s recursion theorem, fixed points exist in every programming language; i.e. in every programming language, there is at least one program (actually infinitely many, trivially different from each other.) the output of which is an exact duplicate of the program.

Attached you will find a fixed point program written in perl.

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