Every derived value should have a derivation.
Data-integrity controls govern the record. When an AI system produces a derived value inside that record, a separate question remains: was the figure derived from the declared source data, by the declared computation?
Certanum is being built to answer that question with evidence, for every consequential figure.
When a person entered the number, attribution implied derivation. When a generative component produces it, the two come apart.
A record can be attributable, contemporaneous, complete and retained while the derivation of a figure inside it remains unevidenced. An AI system can select the wrong source value, apply the wrong operation, or state a figure it never computed — and the output text looks identical in each case.
Output review cannot separate a computed figure from a generated one. A tool-call log establishes that a calculation ran; it does not establish where the values entering it came from.

Where consequential figures arise.
A figure is consequential when it is acted upon, recorded, submitted or defended.
The record already has rules. AI adds a question they were not written for.
Descriptions of regulatory and policy instruments are indicative, are not legal advice, and should be confirmed with qualified counsel. Certanum confers compliance with nothing. It produces evidence an existing assurance, validation or audit process may require.
For every consequential figure: computed, traceable, reproducible — or withheld.
Computed. The figure is produced by declared, deterministic software — not generated by the model.
Traceable. Every operand entering the computation resolves to an authoritative source value, or to a declared, immutable artifact bound by digest.
Reproducible. A third party can re-execute the declared computation over the recorded operands and obtain the released figure.
Withheld when unsupported. An operand that cannot be resolved does not degrade the answer. It withholds it.
The architecture partitions the generative component out of the numerical path: the model interprets; deterministic software computes. That is the same boundary draft Annex 22 draws for critical GMP applications. Certanum is additional to data-integrity and computer-system-validation controls, not a substitute for them.
One workflow. One class of consequential figure. Success criteria agreed before we begin. Certanum funds the initial pilot work.