theorem
proved
born_rule_normalized
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IndisputableMonolith.Measurement.BornRule on GitHub at line 162.
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159 simp [complementAmplitudeSquared, initialAmplitudeSquared, Real.cos_sq_add_sin_sq rot.θ_s]
160
161/-- Born rule normalized: from recognition costs to normalized probabilities -/
162theorem born_rule_normalized (C₁ C₂ : ℝ) (α₁ α₂ : ℂ)
163 (h₁ : Real.exp (-C₁) / (Real.exp (-C₁) + Real.exp (-C₂)) = ‖α₁‖ ^ 2)
164 (h₂ : Real.exp (-C₂) / (Real.exp (-C₁) + Real.exp (-C₂)) = ‖α₂‖ ^ 2) :
165 ‖α₁‖ ^ 2 + ‖α₂‖ ^ 2 = 1 := by
166 have hdenom : Real.exp (-C₁) + Real.exp (-C₂) ≠ 0 :=
167 (add_pos (Real.exp_pos _) (Real.exp_pos _)).ne'
168 calc ‖α₁‖ ^ 2 + ‖α₂‖ ^ 2
169 = Real.exp (-C₁) / (Real.exp (-C₁) + Real.exp (-C₂)) +
170 Real.exp (-C₂) / (Real.exp (-C₁) + Real.exp (-C₂)) := by rw [← h₁, ← h₂]
171 _ = (Real.exp (-C₁) + Real.exp (-C₂)) / (Real.exp (-C₁) + Real.exp (-C₂)) := by
172 simpa using
173 (add_div (Real.exp (-C₁)) (Real.exp (-C₂)) (Real.exp (-C₁) + Real.exp (-C₂))).symm
174 _ = 1 := div_self hdenom
175
176end Measurement
177end IndisputableMonolith