30 setxunit 18 setfontsize -1 7 setxrange -5 7 setyrange /f { ln } def /g {setxvar x -1 add} def /val 3.14 2 div def [1 1 ] {orange} Quadrillage tracerepere marks gsave bleu 1.75 setlinewidth .0001 xmax {f} Courbe grestore {g} courbe $$ y = \ln x $$ 3 -2 [2 dup] cctexlabel $$ y = x-1 $$ 4.5 5 [2 dup] cctexlabel