commit hash instrument
| Definition | The fingerprint git assigns to a snapshot of a repository and its history, which identifies the content exactly and does not by itself prove when it existed. Chronology comes from a public push, a signed tag, or an archival deposit. Chapter 0 section 0.12. Also commit. |
|---|---|
| Example | Commit 3172e00 identifies one snapshot of the book’s repository and every file in it, and says nothing about the clock. |
| Book | Data Mining as Observation, draft 0.2, commit f3914f0; entry id commit-hash, kind instrument. |
| Status | no ledger row names this entry. Corrections: none recorded. |
| Defining equation | none |
| Assumptions and scope |
|
| Prior art | none recorded |
| Evidence | lean/DataMiningAsObservation/Seal.lean |
| Reviewed | semantic review 2026-09-06; generated 2026-09-10 from records at the commits on the provenance page. |
Equation
none
Conditions
- The fingerprint git assigns to a snapshot of a repository together with its history. It identifies exact content, so a changed hash proves a changed file and an equal hash is strong evidence of an unchanged one, but it does not by itself prove when that content existed, since git’s author and committer dates are supplied fields.
- Chronology comes from a public repository receipt, a signed tag, a transparency log, or an archival deposit such as a Zenodo DOI, and a sealed prediction names one of those beside its hash.
Conditions are curated in entries.toml rather than read
from a record.
Ledger
none
First stated
Chapter 0 section 0.12 of Data Mining as Observation, with
the program’s seal ledger,
observation-theory-campaigns/experiments/SEALS.md:1-10,
where every seal is a registration id, a sealing commit, and a hash.
Measurements
none
Failures and corrections
none
Invariance envelope
none declared
Machine checked
lean/DataMiningAsObservation/Seal.lean,
theorems changed_of_hash_ne, hash_eq_of_eq,
exists_collision, at observation-data-mining f3914f0; what
the check covers is stated in the book’s appendix
C.
Used in
Data Mining as Observation primers L and S, chapters 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14.
Related
hash; sealed; sources table; preregistration.
See also
Book equations stated beside the entry’s terms, not defining it: 8.3.
Ledger rows that cite the entry’s records without naming it: OT-7.
Status
Generated 2026-09-10 by encyclopedia/generate.py; book
at observation-data-mining f3914f0; the commit of every record is listed
in the encyclopedia’s provenance.