Could The Product Of Two Debts Really Be A Fortune?

In 628 in the Gurjar capital city of Bhillamala (now, Bhinmal, India), the mathemetician Brahmagupta set out to explain how zero and negatives numbers work.  In his book, Brahmasphutasiddhanta, he set forth the rule that the product of two negative numbers (debts) is a positive number (fortune).  Translating this fundamental mathematical concept into the present century, I’m pondering (pondering, not