proposition: Lemma Rs_x : forall t : R, cos (alphas t) <> 0%R -> Rs t = ((xi intr t - xi intr 0) / cos (alphas t))%R.
proof: Proof. intros; rewrite Rsx; unfold Rminus, Rdiv in |- *; rewrite (Rplus_comm (xi intr 0)); rewrite Rplus_assoc; rewrite Rplus_opp_r; rewrite Rplus_0_r; rewrite Rmult_assoc; rewrite <- Rinv_r_sym; [ rewrite Rmult_1_r; reflexivity | assumption ]. Qed.
imports: Reals trajectory_def trajectory_const constants ycngftys rrho