# When a user (completely) changes their answer via edit

Background story/motivation for question:

I recently saw an answer that presented an incorrect way of solving a problem. (Simple algebra error, $\sqrt{x^2 + y^2} \not = x + y$.)

I let the author know via comment, and ended going back/forth a few times before he understood the error. The user then edited the answer and responded with a comment that (in my opinion) implied that I was the one in error, not himself. (I'm sure it wasn't meant to be ugly/mean, but could be interpreted in several ways--all he posted was an equation.)

Question:

What is the protocol/accepted response when a user edits their own answer beyond recognition, and I've commented on the old answer?

My comments don't apply to the new one (and could, theoretically, be deleted along with the whole (short) back/forth about the error), but I can't delete the whole conversation, so I'm hesitant to delete my side of it.

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