anchor.diff:  
   PLUS  : '+';
   MINUS : '-';
  +MUL   : '*';
  +DIV   : '/';
  +POWER : '**';
   
   // return newlines to parser
   NEWCARD : '\r'? '\n' ;
  
positive.code: }
  }
  
  // parser rules
  
  program : card*;
  
negative.code: ufloatConst : integer=NUMBER? '.' (fraction=NUMBER | fractionE=FLOAT_FRAC exponent=fixedConst)? ;
  floatConst  : sign? unsigned=ufloatConst ;
  
  sign  : (PLUS|MINUS);
  mulOp : (MUL|DIV);
  
  
  // lexer rules
  