anchor.diff:   */
    
   ID      : [a-zA-Z] [a-zA-Z0-9]* ;
  -OP	: ('=' | '!' | '<' | '>')+
  +OP	: ('=' | '!' | '<' | '>' | '-')+
  +PO	: ('-' | '~')
   INT     : ( '0' | [1-9] [0-9]* ) ;
   STRING  : '\'' .*? '\'' ;
   FUNC    : [a-zA-Z] [a-zA-Z0-9_-.:]* ;
  
positive.code:                 ;
  		
  		
  e	: t OP e                # cam_dcBinRel
  	| t
  	;
  t 	: STRING                               # cam_termString
  
negative.code:  * Generic structure
   */
  
  file    : includes body EOF 
          ;
  incl	: 'include' 
  body 	: (comp | defn)*
  	;
  defn    : 'define' ID params? portset '{' atom '}'  # defnAtomic
  