can the number be proved?
rounds on disk that re-derive from their own contents
every answer is written down before anything is counted
A round is an append-only file, one record per call, each record carrying the hash of the one before it. Every report re-derives the chain before it computes a single figure, because a number computed from a round that no longer re-derives is not a number. A failed call is written down with its status and the provider’s own reason rather than retried, since repeating a request until it succeeds is a filter, and a filter applied to evidence is a thumb on the scale.
lulu verify # re-derive every chain on disk, and say what the check does not cover
what a re-derivation proves
Every record present was checked against its own hash and against the one before it, so altering a single answer costs a rewrite of every record after it. A sealed round is also checked against its own length, because it ends with a record saying how many calls it made, which is what turns records deleted from the end into something reported rather than silently lost.
On the rounds this repository was built from, that check reads 6 of 6 rounds re-derive from their own contents.
what it does not prove
It does not prove the provider said what the file says it said. A hash chain makes a record tamper-evident to everyone downstream of it, including you, and it cannot reach back to the other end of the wire. The command prints that limit in its own output rather than leaving the word verified to do work it has not earned.
and the number on a page
A round reaches the web only when somebody runs lulu publish and commits the file it writes, so no measurement is on this site that a person did not choose to put there. Each published page carries the model, the arm, the date and the draw count beside the figure.