The K3 verdict for a system pitch introduced by a ModifyEvent replacement
(never minted — the collision pre-walk excludes ModifyEvent) differed across a
snapshot cut: in-session it slipped through (system_mints had no entry, so the
P12-K3 identity check saw nothing), yet post-snapshot it read
SystemDerivedContentImmutable once the pitch was re-seeded as a system mint.
Per the user's call ("reject the introduction"): modify_event now refuses a
replacement carrying a never-minted SYSTEM-DERIVED pitch id (replica
SYSTEM_DERIVED, not Live in objects) with TargetMissing, before the identity
check. The verdict no longer depends on the registry — the pitch is not live in
objects in either frame — so both refuse identically, closing the asymmetry.
Scoped to the system namespace, where the asymmetry lives (only system pitches
re-seed as system mints): a user-replica pitch carries no namespace claim and
has no snapshot asymmetry, so ModifyEvent may still introduce user pitch
content (the concurrent-modify tests rely on it).
Regression: a_modify_event_introducing_a_never_minted_system_pitch_is_refused_
p13_k1. 938 tests, convergence/conformance green. PASS13: P13-K1 resolved.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Levi Neuwirth
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