SUBROUTINE POP (A, B, C)  
    
      INTEGER  PSTACK (12)  
      INTEGER  PX   
      INTEGER  PEND 
      COMMON   /PPCOM/  PSTACK  
      COMMON   /PPCOM/  PX  
      COMMON   /PPCOM/  PEND
      INTEGER A, B, C   
      PX = PX - 3   
      IF (PX .LE. 0) CALL FATAL (46)
      A = PSTACK (PX)   
      B = PSTACK (PX+1) 
      C = PSTACK (PX+2) 
      RETURN
      END