%% auteur : 

-4 7 setxrange
-2 6 setyrange
50 setxunit
50 setyunit
.5 .5 setquadrillagestep
quadrillage

currentlinewidth 2 mul setlinewidth
traceaxes
axesarrow
ticks
15 setfontsize
/A{2 2.333} def
/B{3.6666 4} def
B point
B dashpoint
A point
A dashpoint
%marks
1 setlinewidth
/f {setxvar
1 3 div  x  add} def
{f} courbe
setTimes
(O) O dltext
setTimesItalic
   (d) -1 -1.5 [2 2] ultext
(a) 0 2.333 [1.5 1.5] ltext
(b) 3.666 0 [1.5 1.5] dtext
setTimes
  (I) 1 0 dtext 
(J) 0 0.9 ltext
(A) A [1.5 1.5] drtext
(B) B [1.5 1.5] drtext
(2) 2 0 [1.5 1.5] dtext
(4) 0 3.9 [1.5 1.5] ltext