400 setheight
400 setwidth
-3 15 setxrange
-3.5 14.5 setyrange
/l 8 def

/a {0 l l} def    
/b {l l l} def    
/c {l 0 l} def    
/d {0 0 l} def    
/e {0 l 0} def 
/f {l l 0} def
/g {l 0 0} def
/h {0 0 0} def
/i {3.5 3.5 l} def
/j {3.5 0 6.5} def
/k {5 6.5 l} def


/vect_I {-15 cos -15 sin} def
/vect_J {35 cos 35 sin .8 mulv} def
/vect_K {0 1} def

/xyz2xy {
3 dict begin
   /z exch def
   /y exch def
   /x exch def
   vect_I x mulv
   vect_J y mulv
   vect_K z mulv
   addv addv
end
} def

[/A /B /C /D /E /F /G /H /I /J /K] 
[a b c d e f g h i j k] {xyz2xy} capply
mapnp

/dotscale {2 dup} def
1.2 setlinewidth

[A B C G F B] ligne
[C D A] ligne
[D H G] ligne

K I A B interdroite /K1 defpoint
K I D C interdroite /K2 defpoint
K2 J C G interdroite /K3 defpoint

I J K paral K2 J interdroite /L defpoint

gsave
   .8 setlinewidth
   pointilles
   [A E H] ligne
   [E F] ligne
   [I J] ligne
   [K L] ligne
   mixte orange
   [K1 K2 K3] ligne
grestore

[I J K L] {times} plot

12 setfontsize
setTimesItalic
   (A) A ultext   
   (B) B urtext	  
   (C) C drtext	  
   (D) D ultext	  
   (E) E brtext
   (F) F brtext   
   (G) G drtext   
   (H) H dltext   
   (I) I (0 2) uctext   
   (J) J (-5 0) cltext   
   (K) K ultext   
   (L) L (-5 0) cltext   
   (d) 8 13 brtext
   (d') 11.5 13 bltext


1.2 setlinewidth
%% xmax L K xdpoint K 1 trait
%% ymin L K ydpoint L 1 trait
I J -1 trait
L K -1 trait