Status: IN
SSI's composed invariant layers provide correct serializable snapshot isolation: MVCC enforces visibility through append-only versions and symmetric deletion rules, and SSI validation ensures own-writes are checked before store consultation, preventing lost updates.
Garbage collector's lack of thread safety could remove versions that active transactions need for visibility checks, violating MVCC invariants
Depends on (SL): transaction-isolation-composes-two-invariant-layers, ssi-own-writes-require-buffer-check
Unless: gc-not-thread-safe