%% PhS
%% 

50 setxunit
-3.5 3.5  setxrange
-3.5 3.5 setyrange




%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% procédures
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

/bddroite {
8 dict begin
	/kd exch def
	/kg exch def
	/By exch def
	/Bx exch def
	/B {Bx By} def
	/Ay exch def
	/Ax exch def
	/A {Ax Ay} def
	gsave
	[A A B vecteur kg mulv addv A A B vecteur kd mulv addv] ligne
	grestore
end
	} def



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% definition d'une couleur
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

/coul1 {120 255 div 70 255 div 9 255 div setrgbcolor} def



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% definition des points
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

/a {1.5} def
/c {2.2} def
/b {c c mul a a mul sub sqrt} def
/e {c a div} def
/Kx {a e div} def
/K {Kx neg 0} def
/K+ {K 0 6 addv} def
/K- {K 0 -6 addv} def
/Kp {Kx 0} def
/Kp+ {Kp 0 6 addv} def
/Kp- {Kp 0 -6 addv} def
/O {0 0} def
/F {c neg 0} def
/Fp {c 0} def
/S1 {a neg 0} def
/S2 {a 0} def
/B {0 b} def

/xdet {settvar t t mul b b mul div 1 add sqrt a mul} def
/ydet {settvar t} def


/Mx {b 0.6 mul xdet} def
/My {b 0.6 mul ydet} def
/M {Mx My} def
/H {M Kp Kp+ orthoproj} def


/bissec {F M Fp bissectrice} def
/T {bissec Kp Kp+ interdroite} def
/U {bissec M perp Kp Kp+ interdroite} def




%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% traces
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

1.2 setlinewidth

[O F Fp S1 S2 K Kp] points
F Fp -0.5 1.5 bddroite



b -2 mul b 2 mul settrange
{xdet} {ydet} courbeparam
b -2 mul b 2 mul settrange
{xdet neg} {ydet} courbeparam

vert
[K+ K-] ligne
[Kp+ Kp-] ligne


0.6 setlinewidth
orange
mixte
a neg b neg a b -1 2 bddroite
a  b neg a neg b -1 2 bddroite
noir
[O 0 -6.5 addv O 0 6.5 addv] ligne



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% texte
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

setTimesItalic
noir
  (O) O [1.5 dup] dltext
  (F) F [1.5 dup] dltext
  (F') Fp [1.5 dup] drtext


<latex>
$ S_1 $
</latex>
  S1 [1.5 dup] dltexlabel

<latex>
$ S_2 $
</latex>
  S2 [1.5 dup] drtexlabel


vert
  (K) K [1.5 dup] drtext
  (K') Kp [1.5 dup] dltext



<latex>
$ \mathcal{D} $
</latex>
K 0 -3 addv [1.5 dup] cltexlabel

<latex>
$ \mathcal{D}' $
</latex>
Kp 0 -3 addv [1.5 dup] crtexlabel