20if (!function_exists(__NAMESPACE__ . 
'\\acsc')) {
 
   21    function acsc($complex): Complex
 
   23        $complex = Complex::validateComplexArgument($complex);
 
   25        if ($complex->getReal() == 0.0 && $complex->getImaginary() == 0.0) {
 
   26            return new Complex(INF);
 
   29        return asin(inverse($complex));
 
An exception for terminatinating execution or to throw for unit testing.