250 H 0 = 1 → Continuous H → (∀ t u, H (t+u) + H (t-u) = 2 * H t * H u) → 251 deriv (deriv H) 0 = -1 → ∀ t, deriv (deriv H) t = -H t 252 253/-- cos satisfies the d'Alembert smoothness hypothesis. -/
used by (3)
From the project-wide theorem graph. These declarations reference this one in their body.