public void Interpret(TextReader reader, IMathSystem system)
 {
     if(scanner == null)
         scanner = new ParserScanner(reader, system);
     else
         scanner.Reset(reader, system);
     scanner.AllStatements();
 }
 public void Interpret(TextReader reader, IMathSystem system)
 {
     if (scanner == null)
     {
         scanner = new ParserScanner(reader, system);
     }
     else
     {
         scanner.Reset(reader, system);
     }
     scanner.AllStatements();
 }