proposition: Lemma Dhy : forall t : R, derive_pt hy t (hy_derivable t) = (- vi intr * sin (rho_vi * t))%R.
proof: Proof. Proof with trivial. intro; unfold hy in |- *; reg... replace (vi intr:R) with (r_vi * rho_vi)%R. ring. unfold rho_vi, r_vi in |- *; unfold r in |- *. field. assert (H := rho_pos (vi intr)); red in |- *; intro; rewrite H0 in H; elim (Rlt_irrefl _ H)... Qed.
imports: Bool Reals trajectory_const rrho trajectory_def constants ycngftys ycngstys Omega