-2.5 3 setyrange -4.5 3.5 setxrange 35 setxunit .5 .5 setquadrillagestep quadrillage /unites {} def tracerepere marks /ymarkstyle {cltext} def /A {1 -1} def /D {2.5 .8} def /B {-4 -1} def /C {3 2} def [B C] points A dashpoint 1.2 setlinewidth /arg {argc} def [B .. -3 0 .. -2 .5 .. -1 0 .. -.5 -1 .. 0 -1.5 {right} .. 1 -1 .. 2 0 .. D .. C] draw .6 setlinewidth pointilles setTimesItalic (O) O dltext (A) A drtext