diff --git a/Compfiles/Usa1992P1.lean b/Compfiles/Usa1992P1.lean index 84074df..bf19c10 100644 --- a/Compfiles/Usa1992P1.lean +++ b/Compfiles/Usa1992P1.lean @@ -126,8 +126,7 @@ lemma Finset.range_prod_odd exact Nat.lt_add_right 1 hi exact hs i this · apply hs - rw [Finset.mem_range] - exact lt_add_one n + exact Finset.self_mem_range_succ n lemma lemma3 {m : ℕ} (hm : (m % 10) + 1 < 10) : (Nat.digits 10 (m + 1)).sum = (Nat.digits 10 m).sum + 1 := by @@ -519,15 +518,6 @@ problem usa1992_p1 (n : ℕ) : case zero => simp case succ n ih2 => rw [Finset.prod_range_succ] - have h10 : 1 ≤ (10 ^ 2 ^ (n + 1) - 1) := by - have h11 : 2 ≤ 2 ^ (n + 1) := by - rw [pow_add, pow_one] - have h12 : 1 ≤ 2 ^ n := Nat.one_le_two_pow - exact Nat.le_mul_of_pos_left 2 h12 - have one_le_ten : 1 ≤ 10 := by norm_num - have h13 : 10 ^ 2 ≤ 10 ^ 2 ^ (n + 1) := - Nat.pow_le_pow_of_le_right one_le_ten h11 - omega exact le_mul_of_le_of_one_le ih2 (ha1 (n + 1)) -- Now b_n = b_{n-1}10^N - b_{n-1}, where N = 2^n.