anchor.diff:  BINARY_SYMBOL: ('~'|'!'|'@'|'%'|'&'|'*'|'-'|'+'|'='|'\\'|'|'|'?'|'/'|'>'|'<'|',') ('~'|'!'|'@'|'%'|'&'|'*'|'-'|'+'|'='|'\\'|'|'|'?'|'/'|'>'|'<'|',')*;
   CHARACTER: '$' . ;
   COMMENT: '"' .* '"' {$channel = HIDDEN;};
  -TAB: '\t';
   WHITESPACE: (' ' | '\n' | '\r' | '\f' )+ {$channel = HIDDEN;};
  +STATEMENT_INDENT: ('\t\t') ('\t')*;
  +METHOD_INDENT: '\t';
  
positive.code: 
  nonEmptyStatements
  	:	'^' expression ('.')?
  	|	expression ('.' statements)?
  	;
  
  expression 
  
negative.code: 	;
  	
  method 
  	:	METHOD_INDENT (PLUS | MINUS) messagePattern (tabbedTemporaries)? tabbedStatements
  	;
  
  messagePattern
  	:	unarySelector
  	|	binarySelector variableName
  	|	(keyword variableName)+
  	;
  
  tabbedTemporaries
    : STATEMENT_INDENT temporaries
    ;
  
  temporaries
  