If you model a restaurant's books as data, a handful of rules carry most of the weight. Prime cost is food cost plus beverage cost plus all labor, divided by sales. Card tips and sales tax are credits to liability accounts that should drain back toward zero. A delivery app payout is a net figure you expand back into sales and expense lines. Everything else is ordinary double entry. I run ZeraBooks, an AI-native general ledger, and restaurant books are a good test of whether a ledger's data mo...