1 setxyrapport
4.5 setxunit
7.5 setborder
90 setangle_repere
-5 50 setxrange
-5 25 setyrange
1 1 settkstep
.5 .5 setsubtkstep
2 2 setmkstep
traceaxes
axesarrow
15 setfontsize


/f {setxvar
#rpn#   12
} def

/A {20 0} def
/B {20 7} def
/C {20 17} def
/D {xmax 17} def
/E {xmax 7} def

/g {setxvar
#rpn#   17
} def

/h {setxvar
#rpn#   7
} def



/fillstyle {{blanc} {0.20  0.80  0.40 setrgbcolor} 0.5 gradientfill} def

20 xmax {g} {h} Fillcourbes

gsave
   bleu
   1 setlinewidth
   continu
 0 xmax  {f} Courbe
grestore

gsave
   vert
   1 setlinewidth
   pointilles
 0 xmax  {g} Courbe
grestore

gsave
   vert
   1 setlinewidth
   pointilles
 0 xmax  {h} Courbe
grestore

setTimesItalic
   (x) xmax 0 (-10 0) ultext
   (y) 0 ymax  (0 -10) drtext
(O) O dltext

gsave
   bleu
   1 setlinewidth
   [20 0 20 25] ligne

<tex>
$n_0$
</tex>
20 0 dctexlabel

<tex>
$l$
</tex>
0 12 cltexlabel
grestore

<latex>
$u_n\in I$ pour $n\geqslant n_0$
</latex>
20 14.5 [1.5 dup] crtexlabel