theorem
proved
THEOREM_angle_coupling_rigidity
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IndisputableMonolith.Measurement.RecognitionAngle.AngleFunctionalEquation on GitHub at line 338.
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335
336This is the master theorem that makes the angle coupling "forced":
337there is no freedom in the choice of H once the axioms are specified. -/
338theorem THEOREM_angle_coupling_rigidity
339 (H : ℝ → ℝ)
340 (hAxioms : AngleCouplingAxioms H)
341 (hReg : AngleStandardRegularity H) :
342 ∀ t, H t = Real.cos t :=
343 dAlembert_cos_solution H
344 hAxioms.normalized
345 hAxioms.continuous
346 hAxioms.dAlembert
347 hAxioms.calibrated
348 hReg.smooth
349 hReg.ode
350 hReg.cont
351 hReg.diff
352 hReg.boot
353
354/-- cos satisfies all angle coupling axioms. -/
355theorem cos_satisfies_axioms : AngleCouplingAxioms Real.cos where
356 dAlembert := cos_dAlembert
357 continuous := Real.continuous_cos
358 normalized := Real.cos_zero
359 calibrated := by
360 have h : deriv (deriv (fun x => Real.cos x)) 0 = -Real.cos 0 := cos_second_deriv_eq 0
361 rw [h]
362 simp [Real.cos_zero]
363
364/-- cos satisfies standard regularity. -/
365theorem cos_satisfies_regularity : AngleStandardRegularity Real.cos where
366 smooth := cos_dAlembert_smooth
367 ode := cos_dAlembert_to_ODE
368 cont := cos_satisfies_continuous_neg