%% gh
%% Illustration de la distributivité

%% échelle et étendue de l'image
60 setxunit
0 7 setxrange
1.5 4.5  setyrange

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% définitions des couleurs
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

/coul0 {0 0 0 0.5 setcmykcolor} def %gris
/coul1 {noir} def
/coul2 {orange} def
/coul3 {rouge} def
/coul4 {bleu} def

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Les initialisations pour l'arbre
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
coul1
1.5 setlinewidth

5 setdboxit 		%% reglage bordure de l’encadrement 
/linearc .1 def 	%% pour arrondir les angles 
setPalatino


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Le premier arbre
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

(node11) bnode
(Ou) 1 4 [1.5 dup] cctext

(node21) bnode
<latex>
$P$
</latex>
.5 3 [1.5 dup] cctexlabel

(node22) bnode
(Et) 1.5 3 [1.5 dup] cctext

(node31) bnode
<latex>
$Q$
</latex>
1 2 [1.5 dup] cctexlabel

(node32) bnode
<latex>
$R$
</latex>
2 2 [1.5 dup] cctexlabel


(node11) (node21) (-) ncline
(node11) (node22) (-) ncline
(node22) (node31) (-) ncline
(node22) (node32) (-) ncline


<latex>
$\equiv$
</latex>
3 3.5 [1.5 dup] cctexlabel


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%% Le deuxième arbre
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

(node11) bnode
(Et) 5 4 [1.5 dup] cctext

(node21) bnode
(Ou) 4 3 [1.5 dup] cctext

(node22) bnode
(Ou) 6 3 [1.5 dup] cctext

(node31) bnode
<latex>
$P$
</latex>
3.5 2 [1.5 dup] cctexlabel

(node32) bnode
<latex>
$Q$
</latex>
4.5 2 [1.5 dup] cctexlabel

(node33) bnode
<latex>
$P$
</latex>
5.5 2 [1.5 dup] cctexlabel

(node34) bnode
<latex>
$R$
</latex>
6.5 2 [1.5 dup] cctexlabel


(node11) (node21) (-) ncline
(node11) (node22) (-) ncline
(node21) (node31) (-) ncline
(node21) (node32) (-) ncline
(node22) (node33) (-) ncline
(node22) (node34) (-) ncline