[carapace]

> No one knows which one is actually correct or used by the customers in practice.

Automating BS is bad.

> Thus, you could say there is no correct answer.

I object to such fatalism.

Kind of the whole point of computers is to find and eliminate such ambiguities.

I don't mind playing irrational games for entertainment, but they are "no basis for a system of government", eh?

> Most software development is wrestling with malleable requirements.

Sure but that's no excuse for automating irrational systems. There's no written requirement that the math to compute totals and taxes shall be mysterious?