12000x · 05 — Phase F · Template + Instance proof (shared piece graph)

Goal

Prove brief items #10 (process_template_as_piece_graph) and #11 (generate_instance_from_template) using existing primitives only. Treat Phase D workflow as the template, then ask fn_iu_compose to build a new collection that references the same 7 piece iu_ids in the same order under a new collection_key. No new piece minting; full lineage carried by iu_id identity.

SQL

WITH template AS (
  SELECT id AS tpl_id, manifest_digest AS tpl_digest
  FROM iu_piece_collection WHERE collection_key='iu_core.12000x.workflow.invoice-approval'
)
SELECT public.fn_iu_compose(
  'iu_core.12000x.workflow.invoice-approval.instance-001','workflow',
  'Invoice approval — Q2 2026 Acme Corp instance',
  format('Instance generated from template_collection_id=%s template_digest=%s', tpl_id, tpl_digest),
  (SELECT jsonb_agg(jsonb_build_object('role','step','iu_id', pm.iu_id) ORDER BY pm.piece_order)
     FROM iu_piece_membership pm
     WHERE pm.collection_id=template.tpl_id AND pm.membership_status='active'),
  'iu-core-12000x')
FROM template;

This is the FIRST live production exerciser of fn_iu_compose's {iu_id:<uuid>} branch (vs the {new_piece:{…}} branch used in D/E).

Live response

{
  "ok": true,
  "collection_id": "7c1b58b4-98fd-4d61-b59c-52b690d624a8",
  "pieces_minted": 0,
  "collection_key": "iu_core.12000x.workflow.invoice-approval.instance-001",
  "collection_kind": "workflow",
  "minted_unit_ids": [],
  "pieces_attached": 7
}

pieces_minted=0, pieces_attached=7 — exact contract.

F.1 — Instance row + lineage

id	manifest_digest	description
7c1b58b4-98fd-4d61-b59c-52b690d624a8	0d1da72850c71618a759cf08709f3825	Instance generated from template_collection_id=84115abf-… digest=0d1da7…

description carries lineage. 13000x candidate: promote to dedicated source_collection_id uuid FK + relation_kind text column.

F.2 — Instance validates

{"ok": true, "errors": [], "warnings": [], "piece_count": 7}

F.3 — Instance render byte-equivalent to template

piece_order	piece_role	canonical_address
0..6	step	iu_core/12000x/wf/invoice/01-receive .. 07-notify

F.4 — Piece-graph identity (headline)

tpl_pieces	inst_pieces	shared_pieces	tpl_only	inst_only
7	7	7	0	0

Set-theoretic identity: every template piece is in the instance and vice versa, ZERO divergence. The instance is not a copy — it is a second view onto the same DAG.

F.5 — Template digest = Instance digest (the formal proof)

template_digest                  = 0d1da72850c71618a759cf08709f3825
instance_digest                  = 0d1da72850c71618a759cf08709f3825

Formal proof that pieces are the primitive design unit. The manifest digest is computed over the piece graph (ordered iu_ids + roles + collection_kind), not over the collection's identity, key, title, or description. Two collections with the same piece graph share the same digest. Downstream consumers (Qdrant indexer, text-as-code exporter, audit-ledger anchor) see them as the same content artefact regardless of access path.

F.6 — v_iu_collection_manifest cross-section

14 rows total (7 per collection); each row references the same iu_id set under two different collection_keys.

Pass criteria

• Instance fn_iu_compose accepted the {iu_id:<uuid>} branch
• pieces_minted=0 (no duplication) and pieces_attached=7
• Instance validates ok
• Instance renders byte-equivalent to template
• Set-identity: shared=7, tpl_only=0, inst_only=0
• Template digest = Instance digest (0d1da72850c71618a759cf08709f3825)
• Description carries template_collection_id lineage
• Post-ROLLBACK: zero leftover collections

PHASE F PASS — Template/Instance Product Factory pattern proven without new substrate.

Carry-forward (13000x candidate)

Promote description lineage to dedicated source_collection_id uuid FK + optional relation_kind text column (instance_of, forked_from, derivative_of). Author-mode only; not blocking this PASS.