+-----MOD_ATT:N-N-----+            
      |          +MOD_ATT:N-+SUBJ:V-+    
      |          |          |       |    
 Association of PFK and __NODE__ occurs .
MOD_ATT:N-N (__NODE__,Association)
MOD_ATT:N-N (__NODE__,PFK)
SUBJ:V-N (occur,__NODE__)

                 +---COMP:V-N(of)---+    
                 |          +SUBJ:V-+    
                 |          |       |    
 Association of PFK and __NODE__ occurs .
COMP:V-N(of) (occur,PFK)
SUBJ:V-N (occur,__NODE__)