-1 7 setxrange -4 1 setyrange 80 setxunit 80 setyunit /H{0 0} def /M{1.5 0} def /B{6 0} def /A{0 -3} def 1.2 setlinewidth M point [M A] ligne pointilles [H A] (<->) ligne [H B] (<->) ligne setTimes (A) A [2 2] dtext (B) B [2 2] urtext (H) H [2 2] ultext (18 m) H A milieu [2 2] ltext (30 m) 3 0.3 [2 2] utext setTimesItalic (M(x)) M [2 2] drtext