( 
  (IP 
    (NP-SBJ 
      (DP 
        (DT 这)
                    
        (QP 
          (CD 一)))
                    
      (ADJP 
        (JJ 重大))
                    
      (NP 
        (NN 突破)))
                    
    (VP 
      (PP-BNF 
        (P 为)
                    
        (IP 
          (NP-SBJ 
            (-NONE- *PRO*))
                    
          (VP 
            (VP 
              (VV 释放)
                    
              (NP-OBJ 
                (NN 政治犯)))
                    
            (CC 和)
                    
            (VP 
              (VV 允许)
                    
              (NP-OBJ 
                (CP 
                  (WHNP-1 
                    (-NONE- *OP*))
                    
                  (CP 
                    (IP 
                      (NP-SBJ 
                        (-NONE- *T*-1))
                    
                      (VP 
                        (VV 流亡)
                    
                        (NP-OBJ 
                          (NN 国外))))
                    
                    (DEC 的)))
                    
                (NP 
                  (NN 人)))
                    
              (IP 
                (NP-SBJ 
                  (-NONE- *PRO*))
                    
                (VP 
                  (VV 回国)))))))
                    
      (VP 
        (VV 铺平)
                    
        (AS 了)
                    
        (NP-OBJ 
          (NN 道路))))
                    
    (PU 。)) )
arg0: 
                    *T*-1 
                
arg1: 
                    国外