Fatal error: Uncaught Error: Call to a member function setVariable() on null in /home/httpd/vhosts/michaelster.ch/httpdocs/lernen/zahlensystem_converter.php:7
Stack trace:
#0 {main}
  thrown in /home/httpd/vhosts/michaelster.ch/httpdocs/lernen/zahlensystem_converter.php on line 7