theorem
proved
tactic proof
mu_pred_upper
show as:
view Lean formalization →
formal statement (Lean)
84theorem mu_pred_upper : mu_pred < (1904 : ℝ) := by
proof body
Tactic-mode proof.
85 unfold mu_pred
86 have he_pos : 0 < electron_pred := electron_pred_pos
87 rw [div_lt_iff₀ he_pos]
88 -- want: proton_binding_pred < 1904 * electron_pred
89 have he_lo : (0.5098 : ℝ) < electron_pred := electron_mass_bounds.1
90 have hp_hi : proton_binding_pred < (970.4 : ℝ) := proton_mass_bounds.2
91 -- proton_binding_pred < 970.4 < 1904 * 0.5098 = 970.6592 < 1904 * electron_pred
92 have step1 : (970.4 : ℝ) < (1904 : ℝ) * (0.5098 : ℝ) := by norm_num
93 have step2 : (1904 : ℝ) * (0.5098 : ℝ) < (1904 : ℝ) * electron_pred := by
94 have h1904 : (0 : ℝ) < 1904 := by norm_num
95 exact mul_lt_mul_of_pos_left he_lo h1904
96 linarith
97