import NNG.Levels.Power.Level_6 Game "NNG" World "Power" Level 7 Title "pow_pow" open MyNat Introduction " Boss level! What will the collectible be? " Statement MyNat.pow_pow "For all naturals $a$, $m$, $n$, we have $(a ^ m) ^ n = a ^ {mn}$." (a m n : ℕ) : (a ^ m) ^ n = a ^ (m * n) := by induction n with t Ht · rw [mul_zero, pow_zero, pow_zero] rfl · rw [pow_succ, Ht, mul_succ, pow_add] rfl LemmaTab "Pow" Conclusion " Apparently Lean can't find a collectible, even though you feel like you just finished power world so you must have proved *something*. What should the collectible for this level be called? But what is this? It's one of those twists where there's another boss after the boss you thought was the final boss! Go to the next level! "