Theorem: Real.exp_one_near_20
File: Mathlib/Data/Complex/ExponentialBounds.lean

Proof steps:
state_before: ⊢ |rexp 1 - 363916618873 / 133877442384| ≤ 1 / 10 ^ 20
state_after: case h

⊢ |rexp 1 - expNear 0 1 (363916618873 / 133877442384)| ≤ |1| ^ 0 / ↑(Nat.factorial 0) * (1 / 10 ^ 20)
tactic: apply exp_approx_start
state_before: case h

⊢ |rexp 1 - expNear 0 1 (363916618873 / 133877442384)| ≤ |1| ^ 0 / ↑(Nat.factorial 0) * (1 / 10 ^ 20)
state_after: case h

⊢ |rexp 1 -
        expNear 21 1
          ((((((((((((((((((((((363916618873 / 133877442384 - 1) * 1 - 1) * 2 - 1) * 3 - 1) * 4 - 1) * 5 - 1) * 6 - 1) *
                                                                    7 -
                                                                  1) *
                                                                8 -
                                                              1) *
                                                            9 -
                                                          1) *
                                                        10 -
                                                      1) *
                                                    11 -
                                                  1) *
                                                12 -
                                              1) *
                                            13 -
                                          1) *
                                        14 -
                                      1) *
                                    15 -
                                  1) *
                                16 -
                              1) *
                            17 -
                          1) *
                        18 -
                      1) *
                    19 -
                  1) *
                20 -
              1) *
            21)| ≤
    |1| ^ 21 / ↑(Nat.factorial 21) *
      (1 / 10 ^ 20 * 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21)
tactic: iterate 21 refine exp_1_approx_succ_eq (by norm_num1; rfl) (by norm_cast) ?_
state_before: case h

⊢ |rexp 1 -
        expNear 21 1
          ((((((((((((((((((((((363916618873 / 133877442384 - 1) * 1 - 1) * 2 - 1) * 3 - 1) * 4 - 1) * 5 - 1) * 6 - 1) *
                                                                    7 -
                                                                  1) *
                                                                8 -
                                                              1) *
                                                            9 -
                                                          1) *
                                                        10 -
                                                      1) *
                                                    11 -
                                                  1) *
                                                12 -
                                              1) *
                                            13 -
                                          1) *
                                        14 -
                                      1) *
                                    15 -
                                  1) *
                                16 -
                              1) *
                            17 -
                          1) *
                        18 -
                      1) *
                    19 -
                  1) *
                20 -
              1) *
            21)| ≤
    |1| ^ 21 / ↑(Nat.factorial 21) *
      (1 / 10 ^ 20 * 1 * 2 * 3 * 4 * 5 * 6 * 7 * 8 * 9 * 10 * 11 * 12 * 13 * 14 * 15 * 16 * 17 * 18 * 19 * 20 * 21)
state_after: case h

⊢ |rexp 1 - expNear 21 1 (36295539 / 44271641)| ≤ |1| ^ 21 / ↑(Nat.factorial 21) * (311834363841 / 610351562500)
tactic: norm_num1
state_before: case h

⊢ |rexp 1 - expNear 21 1 (36295539 / 44271641)| ≤ |1| ^ 21 / ↑(Nat.factorial 21) * (311834363841 / 610351562500)
state_after: case h

⊢ |1 - 36295539 / 44271641| ≤ 311834363841 / 610351562500 - |1| / 22 * ((22 + 1) / 22)
tactic: refine exp_approx_end' _ (by norm_num1; rfl) _ (by norm_cast) (by simp) ?_
state_before: case h

⊢ |1 - 36295539 / 44271641| ≤ 311834363841 / 610351562500 - |1| / 22 * ((22 + 1) / 22)
state_after: no goals
tactic: rw [_root_.abs_one, abs_of_pos] <;> norm_num1