anchor.diff:      ;
   
   channel returns [FormulaAst result]
  -    :   PV {result = channelFromToken($PV.text);}
  +    :   PCHANNEL {result = channelFromToken($PCHANNEL.text);}
       ;
   
   numericLiteral returns [FormulaAst result]
  
positive.code: }
  }
  
  singlePv returns [FormulaAst result]
      :   channel EOF {result = $channel.result;}
      ;
  
  
negative.code:     :  '"' ( ESC_SEQ | ~('\\'|'"') )* '"'
      ;
  
  PCHANNEL
      :  '\'' ( ESC_SEQ | ~('\\'|'\'') )* '\''
      ;
  
  