The refusal was about teardown, and an arena has none

FIX.org

@@ -54,15 +54,38 @@ whatever locals already do; no new borrow regime for globals that locals lack.
 
 [embed] (lib/check.ml:4265) still covers build-time data and is untouched.
 
-** 4. edn both typed and dynamic — QUEUED behind 3
+** 4. edn both typed and dynamic — REDIRECTED to arenas, drop parked
 Two projects, not one. (read-edn T bytes) does not exist — vendor/edn/edn.flan
 is only a tokenizer, and the compile-time struct walk is NEXT.md item 9.
 
-The dynamic half is blocked: a dynamic EDN value is recursive, so it is a Vec
+[drop] was dispatched to unblock the dynamic half and is being PARKED unmerged
-whose element is move-only, which lib/check.ml:599 refuses and whose refusal
+on its branch, not reverted, because the premise was wrong. The refusal at
-names [drop] as the fix. So [drop] gets unstashed — it now has the customer
+check.ml:599 is about *teardown*, not ownership: the type-erased runtime
-NEXT.md:225 said it lacked. Full spec-memory.md:338 scope: recursive teardown
+releases slots bytewise and cannot walk a move-only element. An arena never
-AND the hook. Queued behind 3 because both land in check.ml.
+releases a slot — [free-all] takes the whole region — so the premise does not
+hold there.
+
+That is also what Odin does, which NEXT.md:1620 already recorded: no
+destructors, no drop, no finalizers; [delete] frees container memory and
+nothing else. core:encoding/json ships a hand-written recursive
+[destroy_value] in the *library*, and the idiomatic alternative is to parse
+against temp_allocator and [free_all]. Neither is a language feature. Building
+[drop] was a departure from NEXT.md:1589's settled "defer stays the answer",
+taken on the assistant's prompting and withdrawn.
+
+So: lift check.ml:599 for arena-allocated containers, and let read-edn take an
+allocator — which is already the idiom, since spec-memory.md:283 makes the
+allocator part of the calling convention with an explicit override.
+
+The real cost, stated because it is not free: [can-free] is a RUNTIME
+capability on the allocator value while check.ml:599 is a COMPILE-TIME refusal,
+and the compiler cannot generally know statically that a construction site's
+allocator is an arena. The spec's answer for the analogous drop case is a check
+at the point of construction, one branch per container — a runtime branch. This
+likely becomes a runtime trap rather than a static guarantee.
+
+Ownership tracking itself is untouched. Moves are still tracked; what is given
+up is freeing one element individually, which is the point of an arena.
 
 ** 5. defenum autoincrement — DISPATCHED
 C's rule: no value means previous+1, the first is 0, explicit and implicit mix.