The register
One question, two instruments, and what came back.
Every check we publish, dated and numbered. A check needs only a question worth answering and a second way to answer it — so most of these are of systems we did not build.
Most recent
Do two implementations of “read an amount” agree?
0032 · Ingestion · 10 Sept 2026
Outcomes across 7 checks
2 of 7 are systems we did not build
- Established
- 2
- Divergent
- 4
- Unestablished
- 1
7 checks
- 003210 Sept 2026IngestionDivergent
Do two implementations of “read an amount” agree?
They differed by a factor of one hundred on an ordinary input, and by a sign on another. Both had shipped. Both had passing tests.
- 003109 Sept 2026SchedulingEstablished
Does a roster satisfying all eight constraints exist for seven people?
No. Two weekends require eight distinct people. Proven infeasible, not searched and abandoned.
- 003002 Sept 2026Externalnot in fullDivergent
Does the department's own calculator apply the correct standard deduction?
It does not, under the old regime. Found by computing the same return with a clean-room reference implementation.
- 002928 Aug 2026ExternalEstablished
Do the Finance Bill and the enacted Schedule state the same rates?
They do. Four sources, every figure agreeing — which establishes the rates were not altered between introduction and assent.
- 002824 Aug 2026CLAVISDivergent
Is a salary figure stated net of exemptions being read as gross?
It was. Tax charged on income the exemptions had already removed. ₹49,920 on one return, with the suite green.
- 002722 Aug 2026Cross-cuttingDivergent
Do our own measurement harnesses measure what they claim to?
Eight did not. One compared generated output against its own generator and reported a clean zero.
- 002619 Aug 2026CIPHERnot in fullUnestablished
Does transfer entropy separate causation from correlation at production scale?
Scale is verified at 236 million records; no single result has been written up. A published instrument-level finding would settle it.
How to read an entry
Nine parts, and three of them are never empty.
An entry that only stated a result would be an announcement. The three marked below are what make it a check — and they are the ones a reader should look at first.
- What the two instruments share
Independence is a claim, and a claim without evidence is decoration. Every entry carries a table of what the two computations have in common — module, constants, inputs, and the written rules themselves. A disagreement only proves what the shared parts allow it to prove.
Check 0031 carries a row reading “CORRECTED”. The table originally said the two shared nothing; computing the artifact hashes to publish them showed both lived in one file.
- What the check does NOT settle
Every result has an edge, and the edge is where somebody will misuse it. Naming the limits is what stops an entry being quoted for more than it established.
Check 0029 establishes that four sources agree on a set of rates. It states plainly that agreement is not correctness: if the enacted text itself is wrong, all four reproduce the error.
- What would change the conclusion
A result that nothing could overturn is not a finding, it is a position. Each entry states the observation that would reopen it — and often that observation would be the more valuable one.
Check 0032 says outright that if the two implementations had ever been run against each other, the check would have been unnecessary.
An entry that cannot fill all nine is not published in full. Two in this register are in that state, and each says which of the two reasons applies — held pending notice to a third party, or simply not established yet.
If you think one is wrong
A correction is the most useful thing you can send us.
Every entry states the method in enough detail to be re-run by somebody who has asked us nothing. That is the point of stating it. If a re-run disagrees, we would rather hear it from you than not hear it.
- 01Name the entry and the stepEach reasoning step is numbered so a disagreement can point at one rather than at the conclusion.
- 02Say what you ran and what came backYour environment and your figures. If they differ from ours, that difference is itself the finding.
- 03Say what it would take to settle itBoth readings are usually defensible until somebody names the observation that separates them.
What happens then
If you are right, the entry gains a dated revision saying so, and the correction appears on the company page under its own date. We do not silently edit. Three corrections are already published there, and two of them were found by the act of preparing evidence rather than by anybody complaining.
Established
Both instruments agree. A clean check is a result — the Finance Bill agreeing with the enacted Schedule across four sources is a stronger statement than any one source supports.
Divergent
They disagree, and the entry says which was right. This is what most people mean by a finding, and here it is one outcome of three.
Unestablished
The check could not be completed, and the entry states precisely what would complete it. Publishing this is the part no competitor imitates.