case x:
x
0;
p (
(p)+1);p
q ((p)+(q)+1);p
q ((p)+(q)+1);p
q ((p)+(q)+1);+1 
Prop
x 0;p ((p)+1);pq ((p)+(q)+1);pq ((p)+(q)+1);pq ((p)+(q)+1);
(x)+1
| 1 | case x:x 0;p ((p)+1);pq ((p)+(q)+1);pq ((p)+(q)+1);pq ((p)+(q)+1);+1 |
About:
 |  |  |  |  |  |  |