ISBNs

A ISBN consists of 10 digits and hyphens. The position of the hyphens may vary. A ISBN is valid if the the following equation is true: sum(i = 1 to 10: t * digit[i]) mod 11 = 0

ISBNFixture
isbnstripped?valid?
3-86680-192-03866801920true
3-86680-192-23866801922false
3-680-08783-73680087837true
193239480X193239480Xtrue