- What we claimed
- That the constraint model and its checker shared "no module, helper or constant".
- What was actually true
- Computing the artifact hashes to publish them showed both live in ONE file, with an identical sha256, sharing the input data and the constraint parameters.
- What changed as a result
- Two rows moved from "not shared" to "shared". The conclusion — that no such roster exists — is unaffected, because it rests on a pigeonhole argument verified by hand. What was wrong was the strength of the independence claim, not the result.
Company
A computed answer earns belief only from an instrument that could not have made the same mistake.
That sentence is the whole company. Everything below it — the products, the engagements, the register — is an attempt to hold ourselves to it in public, including on the occasions we have failed to.
- Founded
- 2026
- Base
- India
- Practice
- Verification engineering
- Instruments
- CLAVIS live · CIPHER in build
- Checks published
- See the register
The practice
ProServiq is not a product company that also writes about method
It is a verification practice. A product is what happens when a domain meets all four conditions and the method is worth embodying permanently.
If every instrument we have built disappeared tomorrow, the practice would be unchanged. The thesis does not depend on owning a codebase; it depends on there being computations somebody acts on that nothing independent checks — and there is no shortage of those.
This is why the register is organised around checks rather than findings. A finding requires a product you built to have been wrong. A check requires only a question and a second way to answer it, which means the supply of them is not bounded by our own codebase. The register enforces that structurally: no more than half of it may come from any one system, and the lead entry may not come from a product of ours at all.
A product, then, is not the business. It is the shape the method takes when a domain is worth returning to — where the answer matters, nothing independent checks it, a different second computation is genuinely possible, and the failure is silent.
The practice
Verification engineering, applied to whatever computation is in front of it. Published as checks.
The instruments
Domains that earned a permanent one. See what exists →
Corrections
Where we have been wrong, dated
A practice arguing that systems should be checked by something able to disagree with them has to publish the occasions its own work was found wrong. An empty section here would mean the checking had stopped.
- What we claimed
- Time to prove infeasibility: 0.049 s.
- What was actually true
- That figure came from a different machine and had been copied into prose rather than read from the run. The correct figure on the stated environment is 0.089 s.
- What changed as a result
- The page now renders every timing from the generated state file rather than from written copy, so the same class of error cannot recur silently.
- What we claimed
- That an SMTP 250 response establishes a mailbox exists and a 550 establishes it does not.
- What was actually true
- RFC 5321 does not support either reading. A 250 means the server accepted the forward-path for delivery; a 550 can be policy rather than absence; and a server may accept and reject later.
- What changed as a result
- Restated as accepted, rejected, and indeterminate — which is the three-state shape the rest of the site argues for, and which the original copy had itself flattened to two.
Two of the three above were found by the act of preparing evidence for publication — computing a hash, reading a figure back off a run. That is not a coincidence, and it is the argument for publishing at all.
Standards
Four rules that decide arguments here
Not values. Rules — each one has settled a real disagreement about what to build or what to publish.
01
Three states, never two
Every check reports established, divergent, or unestablished. The third is not a failure to reach an answer — it is an answer, and it is the one most systems throw away. A confident zero where the honest report is "could not be established" is the defect this practice exists to name.
02
Independence is a claim, so it carries evidence
Saying two instruments are independent is worth nothing on its own. Every check we publish carries a table of what the two share — module, constants, inputs, and the written rules themselves — because a disagreement only proves what the shared parts allow it to prove.
03
A refusal names what would change it
A system that declines without saying what was missing is an outage with better manners. Every refusal we build states the fact it could not establish and what would establish it.
04
The measurement is checked before the finding is
A harness that measures the wrong thing returns a confident number, and a confident number stops the search. We have caught eight of our own doing exactly that. Check 0027 is the record.
The boundary
What we will not claim
These are not disclaimers. They are the edges of what this practice is competent and licensed to do, and each has already stopped a piece of work.
We do not represent taxpayers, or anyone else, before any authority.
Representation is professional work under the relevant statutes. We are not registered for it, and building software adjacent to a profession does not confer its licence.
We do not rank investments or assess their suitability.
That is investment advice and requires registration to give. Our instruments state facts about statutory instruments and compute their effect exactly; they do not tell anyone what to buy.
We do not publish a check we have not re-run from the method as written.
A result that cannot be reproduced from the published method is a claim, not a check. Where we hold material we cannot yet publish in full, the register says so rather than presenting a summary as an entry.
We do not describe a finding about a third party until it has been put to them.
Check 0030 concerns a computation we did not build and is held unpublished for exactly this reason. The register states its state rather than omitting it.
If a computation in your business is wrong today, what would tell you?
Found something wrong here?
A correction to anything on this site is the most useful thing you can send us, and it goes into the register above under its own date.
contact@proserviq.com