Section trajectory.
Unset Standard Proposition Elimination Names.
Variable intr : Trajectory.
Variable evad : EvaderTrajectory.
Variable T : TimeT.
unfold thetat in |- *; apply (cond_diff (theta intr)).
Qed.
Definition xe : R := x (tr evad) T.
Definition ye : R := y (tr evad) T.
Definition ve : R := v (h (tr evad)).
Definition r_vi : R := r (vi intr).
Definition rho_vi : R := rho (vi intr).
Definition Die (ti te : R) : R :=
sqrt
(Rsqr (xi intr ti - x (tr evad) te) + Rsqr (yi intr ti - y (tr evad) te)).
Definition conflict (t : R) : bool :=
match Rle_dec (Die t t) ConflictRange with
| left _ => true
| right _ => false
end.
intro; unfold xi, vi, thetat in |- *.
assert (H := cond_x intr t).
rewrite <- H.
apply pr_nu.
Qed.
intro; unfold yi, vi, thetat in |- *.
assert (H := cond_y intr t).
rewrite <- H.
apply pr_nu.
Qed.
Definition l : R := Die 0 T.
Definition d : R := Die 0 0.
Axiom
beta_exists :
{ beta : R |
xe = (l * cos beta + xi intr 0)%R /\
ye = (yi intr 0 - l * sin beta)%R /\
(0 <= beta + thetat intr 0 < 2 * PI)%R }.
Definition beta := let (a,_) := beta_exists in a.
unfold beta in |- *; case beta_exists; trivial.
Qed.
Definition Omega (a : R) : bool :=
match Rle_dec (PI / 2) a with
| left _ =>
match Rle_dec a (3 * (PI / 2)) with
| left _ => true
| right _ => false
end
| right _ => false
end.
Proof with trivial.
generalize beta_def; intro; elim H...
Qed.
Proof with trivial.
generalize beta_def; intro; elim H; intros _ H0; elim H0...
Qed.
Proof with trivial.
unfold d in |- *; unfold Die in |- *; rewrite Rsqr_sqrt...
replace (xi intr 0 - x (tr evad) 0)%R with
(xi intr 0 - xe + (xe - x (tr evad) 0))%R...
replace (yi intr 0 - y (tr evad) 0)%R with
(yi intr 0 - ye + (ye - y (tr evad) 0))%R...
repeat rewrite Rsqr_plus; cut ((ye - y (tr evad) 0)%R = 0%R)...
intro; rewrite H; repeat rewrite Rmult_0_r; rewrite Rsqr_0;
repeat rewrite Rplus_0_r; cut ((xe - x (tr evad) 0)%R = (ve * T)%R)...
intro; rewrite H0;
replace
(Rsqr (xi intr 0 - xe) + Rsqr (ve * T) + 2 * (xi intr 0 - xe) * (ve * T) +
Rsqr (yi intr 0 - ye))%R with
(Rsqr (ve * T) + (Rsqr (xi intr 0 - xe) + Rsqr (yi intr 0 - ye)) +
2 * (xi intr 0 - xe) * (ve * T))%R...
cut (Rsqr l = (Rsqr (xi intr 0 - xe) + Rsqr (yi intr 0 - ye))%R)...
intro; rewrite <- H1; rewrite xe_0; ring...
unfold l in |- *; unfold Die in |- *; rewrite Rsqr_sqrt;
[ unfold xe, ye in |- * | apply Rplus_le_le_0_compat; apply Rle_0_sqr ]...
ring...
unfold xe, ve in |- *; rewrite (tr_cond1 evad); ring...
unfold ye, ve in |- *; rewrite (tr_cond2 evad); unfold Rminus in |- *;
rewrite Rplus_opp_r...
ring...
ring...
apply Rplus_le_le_0_compat; apply Rle_0_sqr...
Qed.
Definition yp (t : R) : R :=
(- sin (thetat intr 0) * (xi intr t - xe) +
cos (thetat intr 0) * (yi intr t - ye))%R.
Hint Resolve xi_derivable yi_derivable: diff.
unfold yp in |- *; set (thetat_p := thetat intr); set (xi_p := xi intr);
set (yi_p := yi intr); reg.
apply (yi_derivable intr).
apply (xi_derivable intr).
Qed.
Hint Resolve yp_derivable: diff.
Definition xp (t : R) : R :=
(cos (thetat intr 0) * (xi intr t - xe) +
sin (thetat intr 0) * (yi intr t - ye))%R.
unfold xp in |- *; set (thetat_p := thetat intr); set (xi_p := xi intr);
set (yi_p := yi intr); reg.
apply (yi_derivable intr).
apply (xi_derivable intr).
Qed.
Hint Resolve xp_derivable: diff.
Definition Rsqr_evader_distance (t : R) : R :=
(Rsqr (xi intr t - xe) + Rsqr (yi intr t - ye))%R.
unfold Rsqr_evader_distance in |- *.
set (xi_p := xi intr); set (yi_p := yi intr); reg.
apply (yi_derivable intr).
apply (xi_derivable intr).
Qed.
Hint Resolve Rsqr_evader_distance_derivable: diff.
Definition Rsqr_intruder_distance (t : R) : R :=
(Rsqr (xi intr t - xi intr 0) + Rsqr (yi intr t - yi intr 0))%R.
unfold Rsqr_intruder_distance in |- *; set (xi_p := xi intr);
set (yi_p := yi intr); reg.
apply (yi_derivable intr).
apply (xi_derivable intr).
Qed.
Hint Resolve Rsqr_intruder_distance_derivable: diff.
intro; unfold Rsqr_evader_distance in |- *; apply Rplus_le_le_0_compat;
apply Rle_0_sqr.
Qed.
intro; unfold Rsqr_intruder_distance in |- *; apply Rplus_le_le_0_compat;
apply Rle_0_sqr.
Qed.
Definition e (t : R) : R := sqrt (Rsqr_evader_distance t).
Definition i (t : R) : R := sqrt (Rsqr_intruder_distance t).
Proof with trivial.
unfold conflict in |- *; cut (e T = Die T T)...
intro; case (Rle_dec (Die T T) ConflictRange); intros;
[ rewrite H; exact r | elim diff_false_true ]...
Qed.
Proof with trivial.
intro; cut (e T = Die T T)...
intro; rewrite H0 in H; unfold conflict in |- *;
case (Rle_dec (Die T T) ConflictRange); intro...
elim n; assumption...
Qed.
rewrite xe_0; rewrite ye_0; unfold Rminus in |- *;
rewrite <- (Rplus_comm (- (l * sin beta))); repeat rewrite Rplus_assoc;
repeat rewrite Rplus_opp_r; repeat rewrite Rplus_0_r;
rewrite <- Rsqr_neg; repeat rewrite Rsqr_mult;
rewrite <- (Rmult_comm (Rsqr (sin beta))); rewrite sin2;
unfold Rminus in |- *; rewrite Rmult_plus_distr_r;
ring.
Qed.
intro; apply Rsqr_incr_0.
rewrite Rsqr_plus.
cut
(Rsqr l =
(Rsqr (e t) + Rsqr (i t) +
2 *
((xe - xi intr t) * (xi intr t - xi intr 0) +
(ye - yi intr t) * (yi intr t - yi intr 0)))%R).
intro.
rewrite H.
apply Rplus_le_compat_l.
repeat rewrite Rmult_assoc.
apply Rmult_le_compat_l.
left; prove_sup0.
unfold e, i in |- *.
unfold Rsqr_evader_distance, Rsqr_intruder_distance in |- *.
rewrite (Rsqr_neg (xi intr t - xe)).
rewrite (Rsqr_neg (yi intr t - ye)).
replace (- (xi intr t - xe))%R with (xe - xi intr t)%R.
replace (- (yi intr t - ye))%R with (ye - yi intr t)%R.
apply sqrt_cauchy.
ring.
ring.
rewrite L.
unfold e, i in |- *.
repeat rewrite Rsqr_sqrt.
unfold Rsqr_evader_distance, Rsqr_intruder_distance in |- *.
replace (xe - xi intr 0)%R with (xe - xi intr t + (xi intr t - xi intr 0))%R.
replace (ye - yi intr 0)%R with (ye - yi intr t + (yi intr t - yi intr 0))%R.
repeat rewrite Rsqr_plus.
rewrite (Rsqr_neg (xe - xi intr t)).
rewrite (Rsqr_neg (ye - yi intr t)).
replace (- (xe - xi intr t))%R with (xi intr t - xe)%R.
replace (- (ye - yi intr t))%R with (yi intr t - ye)%R.
ring.
ring.
ring.
ring.
ring.
apply Rsqr_intruder_distance_pos.
apply Rsqr_evader_distance_pos.
unfold l in |- *; unfold Die in |- *.
apply sqrt_positivity.
apply Rplus_le_le_0_compat; apply Rle_0_sqr.
unfold e, i in |- *; apply Rplus_le_le_0_compat; apply sqrt_positivity.
apply Rsqr_evader_distance_pos.
apply Rsqr_intruder_distance_pos.
Qed.
unfold l in |- *; unfold Die in |- *; apply sqrt_positivity;
apply Rplus_le_le_0_compat; apply Rle_0_sqr.
Qed.
intro.
apply Rsqr_incr_0.
rewrite Rsqr_plus.
cut
(Rsqr (e t) =
(Rsqr l + Rsqr (i t) +
2 *
((xi intr t - xi intr 0) * (xi intr 0 - xe) +
(yi intr t - yi intr 0) * (yi intr 0 - ye)))%R).
intro.
rewrite H.
apply Rplus_le_compat_l.
repeat rewrite Rmult_assoc.
apply Rmult_le_compat_l.
left; prove_sup0.
cut (l = sqrt (Rsqr (xe - xi intr 0) + Rsqr (ye - yi intr 0))).
intro.
rewrite H0.
unfold i in |- *.
unfold Rsqr_intruder_distance in |- *.
rewrite (Rsqr_neg (xe - xi intr 0)).
rewrite (Rsqr_neg (ye - yi intr 0)).
replace (- (xe - xi intr 0))%R with (xi intr 0 - xe)%R.
replace (- (ye - yi intr 0))%R with (yi intr 0 - ye)%R.
rewrite <-
(Rmult_comm
(sqrt (Rsqr (xi intr t - xi intr 0) + Rsqr (yi intr t - yi intr 0))))
.
apply sqrt_cauchy.
ring.
ring.
apply Rsqr_inj.
apply l_is_pos.
apply sqrt_positivity; apply Rplus_le_le_0_compat; apply Rle_0_sqr.
rewrite Rsqr_sqrt.
apply L.
apply Rplus_le_le_0_compat; apply Rle_0_sqr.
rewrite L.
unfold e, i in |- *.
repeat rewrite Rsqr_sqrt.
unfold Rsqr_evader_distance, Rsqr_intruder_distance in |- *.
replace (xi intr t - xe)%R with (xi intr t - xi intr 0 + (xi intr 0 - xe))%R.
replace (yi intr t - ye)%R with (yi intr t - yi intr 0 + (yi intr 0 - ye))%R.
repeat rewrite Rsqr_plus.
rewrite (Rsqr_neg (xe - xi intr 0)).
rewrite (Rsqr_neg (ye - yi intr 0)).
replace (- (xe - xi intr 0))%R with (xi intr 0 - xe)%R.
replace (- (ye - yi intr 0))%R with (yi intr 0 - ye)%R.
ring.
ring.
ring.
ring.
ring.
apply Rsqr_intruder_distance_pos.
apply Rsqr_evader_distance_pos.
unfold e in |- *.
apply sqrt_positivity.
apply Rsqr_evader_distance_pos.
apply Rplus_le_le_0_compat.
apply l_is_pos.
unfold i in |- *.
apply sqrt_positivity.
apply Rsqr_intruder_distance_pos.
Qed.

Lemma L_i : forall t : R, (i t <= l + e t)%R.