Rewriting a fixed number of times

Stream: new members

[Ben Nale]

Hi! I always wondered about this.

1. How do I rewrite something say exactly twice and not more?
2. How do I rewrite something until it can't be rewritten anymore.

[Damiano Testa]

For 2, you can do repeat rw [lem]. In most cases, you can probably achieve the same using simp only [lem].

For 1, I thought that there was a repeat_for, but I cannot find it.