-4.1 5 setxrange -2 5.1 setyrange /A {-1 0} def /B {-4 2} def /U {-2 5} def /u {6 -2} def /V {4 1} def /v {-3 1} def quadrillage [A B] points 20 setfontsize setTimesItalic (A) A urtext (B) B urtext [U V] points U dupp u addv (->) line V dupp v addv (->) line