%% auteur : Gilles Mora

-5.5 3 setxrange
-1.5 2.5 setyrange
45 setxunit
45 setyunit

/quadrillagewidth[.7 .4 .1] def
[1 1 .5 .5 .5 .5]{.7 setgray} Quadrillage

1.2 setlinewidth
%0.5 0.5 setsubtkstep
traceaxes
ticks
marks
tracerepere
axesarrow

/A{-5 1} def
/B{-4 0} def
/J{-3 -1} def
/C{-2 0} def
/D{-1.5 1} def
/E{-.5 2} def
/F{0 1.5} def
/G{0.5 1} def
/H{1 0} def
/I{2 -.5} def
1.3 setlinewidth
[A{-60 dir} .. B .. J{right} .. C .. D .. E {right}.. F .. G .. H .. I] draw
[A B C D E F G H I J] points
<tex>
$C_f$
</tex>
7 4 [1.5 dup] dctexlabel

setTimes
%(1) 1 0 [1.5 1.5] dtext
%(1) 0 1 [1.5 1.5] ltext
(O) O [1.5 1.5] dltext
setTimesItalic
   (x) xmax 0 (-10 0) ultext
   (y) 0 ymax  (0 -10) drtext
<tex>
$C_f$
</tex>
-4.5 .9 [1.5 dup] dctexlabel