Human-Readable vs Machine-Readable Authority

After this lesson, the reader should understand:

• 01Separate the authority itself from its human and machine expressions.
• 02Explain why parallel expressions require an explicit precedence rule.
• 03Describe how ambiguity surfaces when a policy is expressed twice.

Tax guidance and its calculator

When an official calculator and the published guidance disagree, which one is the authority?

The legal hierarchy may already resolve this in principle^[1] — statute and published guidance typically outrank a calculator. But that hierarchy exists in law, not in the calculator itself: nothing in the software represents its own subordination, so a divergence goes uncaught until a person notices, usually during an audit. Under computable authority the relationship is made explicit before release: either the artifact is authoritative and the prose is explanatory, or the prose is authoritative and the artifact is a compiled representation whose divergence is a defect to be corrected under version control^[2]. A precedence rule that exists only in law is not yet a precedence rule the machine can enforce. The cost of leaving precedence implicit is not hypothetical. Australia's income-compliance programme — 'Robodebt' — raised debts by averaging annual tax-office income across fortnights^[3], a method the law did not authorise; the system ran for years before the divergence was conceded, and a Royal Commission later examined how it persisted. The legal hierarchy was clear throughout. The software simply had no representation of its own subordination to it. The objection runs the other way: making any artifact authoritative hands lawmaking to engineers. It would, if engineers chose the precedence. They should not. Precedence is a decision for the issuing authority, recorded in the artifact itself, and the conservative default — prose governs, the artifact is a compiled representation, divergence is a defect — leaves legal authority exactly where it was. What changes is that the subordination becomes machine-checkable rather than assumed.

• Should the artifact ever be the primary legal instrument?
• What review process should a compiled artifact pass before issue?
• How is divergence between the two forms detected?
• Who should decide precedence between the two forms, and where should that decision be recorded so a machine can read it?

No responses yet. Be the first to answer one of the questions above.

Express one rule in both forms.

1. 01Write the rule as an institution would publish it.
2. 02Write the same rule as conditions and an outcome.
3. 03List every difference in meaning between the two.
4. 04Decide which form governs, and record why.