anchor.diff:  	
   
   program
  -	: a=LTERM* sourceElements LTERM* EOF -> ^(PROG sourceElements) // omitting LTERM and EOF
  +	: a=LTERM*  sourceElements LTERM* EOF -> ^(PROG sourceElements) // omitting LTERM and EOF
   
   	;
   
  
positive.code: 	;
  	
  emptyStatement
  	: ';'
  	;
  	
  expressionStatement
  
negative.code: 	;
  	
  statementBlock
          : '{' LTERM* '}' 
  	| '{' LTERM* (statementList->statementList) LTERM* '}' 
  
  	; 
  	
  statementList
  	: (LTERM* statement)+ -> ^(SLIST statement+)
  	;
  	
  variableStatement
  