anchor.diff:  statementContents returns [r]
       : e=expression      { r = e }
       | i=importStatement { r = i }
  -;
  -
  -functionCall returns [r]
  -    : #(LPAREN f=symbol a=expression) { r = EeyFunctionCall( f, (a,) ) }
   ;
   
   expression returns [r]
  
positive.code:     | f=functionCall { r = f }
  ;
  
  symbol returns [r]
      : f:SYMBOL { r = EeySymbol( f.getText() ) }
  ;
  
negative.code:     | importStatement
  ;
  
  initialisationOrExpression :
      expression ( SYMBOL EQUALS^ expression )?
  ;
  
  importStatement :
      "import"^ SYMBOL
  ;
  
  expression :
      simpleExpression ( ( PLUS^ | GT^ ) expression )?
  ;
  