The reduction-version check is a tautology: reduction_version_for seeds
a superblock from the canonical base's self-report, and open compares
the base against that superblock. Both operands descend from the same
source. It catches a corrupt base disagreeing with its superblock, and
necessarily passes for a conformingly propagated stale one.
Rulings: a typed BundleCapabilities required at both constructors and
carried on the Bundle, with no default; outright rejection on mismatch
via CanonicalBaseRequiresRebuild, not read-only and not an anomaly.
Storing the capability keeps all 57 commit sites unchanged; only open
(57) and create (32) move.
Pin 2a stays an open question. Baseline zero does not preserve the
corpus, and after S16 moves the authority to one, a pre-S27 base that
happens to carry one is indistinguishable from a legitimately rebuilt
S16 base. A raw u32 has no provenance. Four candidate dispositions are
recorded, including FORMAT_MINOR as a carrier, which is rejected here
for two independent reasons: the header never changes after creation
(core_spec.tex:10799) so a legacy bundle that commits a validated base
keeps its old minor forever, and a minor change may only append
append-safe discriminants (core_spec.tex:12258), not alter acceptance
semantics — while current readers ignore minor entirely, so the
boundary would bind only readers that already comply.
What survives: provenance must be carried by a container property old
readers cannot silently accept and a later commit cannot inherit
unchanged. That is a format-epoch design, filed next as P13-S28.
Three claims of mine died while scoping this, all recorded in the
contract: a constructor-grep that could not see a propagated value, a
head -14 truncation behind a universal negative, and reading
`format_major != FORMAT_MAJOR` for the half that supported the
proposal. A contract about unobservable defects should carry its own.
Docs only. Not dispatchable. S16 and S27 both remain blocked.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01QjsEnYhm1gPpf6ii2iFxFV
Levi Neuwirth
79a2507d47