IEEE 754 cannot represent 0.10 exactly, and rounding drift across thousands of transactions becomes a real reconciliation shortfall against a real bank statement. Decimal types exist for this exact reason. This is the book's shortest law because there is nothing to negotiate.
Each law names a structural truth about AI-assisted development — independent of model choice, stable across versions. The full treatment, with working examples in C#, Java, Python, and TypeScript, is in the book. Free, no email gate.