anchor.diff:      : objectPrivilege (COMMA objectPrivilege)* onObjectClause
       FROM grantees
       (CASCADE CONSTRAINTS | FORCE)?
  +    ;
  +    
  +revokeRolesFromPrograms
  +    : (roleNames | ALL) FROM programUnits
       ;
positive.code:     ;
      
  granteeIdentifiedBy
      : userName (COMMA userName)* IDENTIFIED BY STRING (COMMA STRING)*
      ;
      
  grantObjectPrivilegeClause
  
negative.code:     ;
      
  grantObjectPrivilege
      : objectPrivilege columnList? 
      ;
  
  objectPrivilege
  