Fatal error: Uncaught Error: Class 'ChrisKonnertz\StringCalc\Symbols\AbstractFunction' not found in /var/www/drupal/sites/energiatalgud/vendor/chriskonnertz/string-calc/src/ChrisKonnertz/StringCalc/Symbols/Concrete/Functions/ATanFunction.php:12 Stack trace: #0 {main} thrown in /var/www/drupal/sites/energiatalgud/vendor/chriskonnertz/string-calc/src/ChrisKonnertz/StringCalc/Symbols/Concrete/Functions/ATanFunction.php on line 12