anchor.diff:  ZONE
       : Z O N E
       ;
  +
  +
  
positive.code:     : U P D A T E
      ;
  
  USER
      : U S E R
      ;
  
  USING
      : U S I N G
      ;
  
negative.code:     : C O N S T R A I N T S
      ;
  
  CURRENT_TIMESTAMP
      : C U R R E N T UL_ T I M E S T A M P
      ;
  