theorem
proved
tactic proof
alpha_lower_bound
show as:
view Lean formalization →
formal statement (Lean)
97theorem alpha_lower_bound : (0.00729 : ℝ) < Constants.alpha := by
proof body
Tactic-mode proof.
98 -- From the rigorous interval proof: alphaInv < 137.039 ⇒ 1/137.039 < alpha
99 have h_inv_lt : Constants.alphaInv < (137.039 : ℝ) := by
100 simpa [Constants.alphaInv] using (IndisputableMonolith.Numerics.alphaInv_lt)
101 have h_inv_pos : (0 : ℝ) < Constants.alphaInv := by
102 have h := IndisputableMonolith.Numerics.alphaInv_gt
103 linarith
104 -- Invert inequality (antitone on positive reals).
105 have h_one_div : (1 / (137.039 : ℝ)) < 1 / Constants.alphaInv := by
106 exact one_div_lt_one_div_of_lt h_inv_pos h_inv_lt
107 -- Translate to alpha = 1/alphaInv and weaken the numeric constant to 0.00729.
108 have h_num : (0.00729 : ℝ) < (1 / (137.039 : ℝ)) := by norm_num
109 simpa [Constants.alpha, one_div] using lt_trans h_num h_one_div
110