Self referential equations

[Simmer]

Is there a mathematical way to represent the formula itself?

i.e. this sentence is about itself being informative

[mathematic]

Clarify your question.  By example?

[HallsofIvy]

I believe that " this sentence is about itself being informative"  WAS an example.  Unfortunately, I have no idea what the sentence means!

I suppose you could write "p-> (p-> i)" where "p" is "this sentence" and "i" is "is informative".