Record that child (a freshly memoized concat result) extends parent
(the immediately-preceding same-generation concat result). Passing a null
parent — the first level after a reset, which extends nothing — clears any
stale entry so the append gate rejects it.
Linking a child also DELETES the parent's own entry, capping the chain at
depth 1 (see the module retention contract). The parent's entry was only
needed for the parent's own commit-gate check; if that commit is still in
flight when the next concat supersedes it, its gate reads undefined and
takes the (safe) full-rewrite path.
Record that
child(a freshly memoized concat result) extendsparent(the immediately-preceding same-generation concat result). Passing a null parent — the first level after a reset, which extends nothing — clears any stale entry so the append gate rejects it.Linking a child also DELETES the parent's own entry, capping the chain at depth 1 (see the module retention contract). The parent's entry was only needed for the parent's own commit-gate check; if that commit is still in flight when the next concat supersedes it, its gate reads
undefinedand takes the (safe) full-rewrite path.