anchor.diff:  grammar clu;
   
   module
  -   : equate? (procedure | iterator | cluster)
  +   : equate* (procedure | iterator | cluster)
      ;
   
   procedure
  
positive.code:    ;
  
  cluster_body
     : equate* 'rep' '=' type_spec (equate (',' equate)*) (own_var (',' own_var)*) 'routine' (routine (',' routine)*)
     ;
  
  routine
  
negative.code:    ;
  
  signals
     : 'signals' '(' exception (',' exception)* ')'
     ;
  
  exception
  