This component is a C# extension that contains a single function implementing the “Elfproef” algorithm as described here: https://nl.wikipedia.org/wiki/Sofinummer
The code is taken from here: https://robboxman.wordpress.com/2008/09/25/elfproef-algorithm-in-c-for-the-dutch-burgerservicenummer/
The function takes a string BSN no as input, and returns a boolean indicating its validity. The BSN should contain exatly 9 digits and should pass a variant of the "11 Test".