#27 · the return is declared

1. 139Record #27 enters the logLOG · append

   a wave is settlingengine: next: #25membrane: waiting at #25

   1. #0a listener
   2. #1a doer
   3. #2listener: the charter
   4. #3doer: the author
   5. #4listener: charter seen
   6. #5listener: blueprint seen
   7. #6doer: the planner
   8. #7listener: assess · charter
   9. #8listener: assess · result
   10. #9doer: the evaluator
   11. #10the charter wanted
   12. #11the blueprint
   13. #12readiness
   14. #13readiness
   15. #14a request: a charter
   16. #15the charter proposed
   17. #16the charter defined
   18. #17readiness
   19. #18readiness
   20. #19a request: a Cell
   21. #20the seed
   22. #21the Cell is open
   23. #22inner listener
   24. #23inner doer
   25. #24the Cell's context
   26. #25return listenerenginemembrane
   27. #26return doer
   28. #27the return addressnew
   29. ·end of the log

   What	before		after
   records in the log	27	→	28
   #27	—	→	the return address · return.declared

   The door adds #27: the return address — which slot to fill, and as what kind of fact.

   Where it happens appendEmissions()Vol. 02 §4.1 · Vol. 03 §1

   The only function that adds records to the log. Each new record gets the next free number, at the end.

   Specification

   Vol. 02 §4.1 · Vol. 03 §1

   Code

   appendEmissions() in core/registers/append-emissions.ts, line 14: the new record gets the next free number

   Journal

   LOG · append · offset: 27, kind: domain.fact · by engine

   Picture

   records in the log: 27 → 28

   1. 1// The one LOG writer (Vol. 02 §4.1, Vol. 03 §1): emissions become tuples by
   2. 2// receiving the next dense absolute offset — `base + window.length` — and
   3. 3// nothing else ever grows the log. Each append is journalled under the
   4. 4// ambient context, so a batch born of a propagated tuple carries that
   5. 5// tuple's offset as its cause — the cube's provenance line (ADR-002).
   6. 6
   7. 7import type { WaveEmission, WaveTuple } from "../wave/gate";
   8. 8import type { RegisterFile } from "./register-file";
   9. 9import { recordTransition } from "./record-transition";
   10. 10
   11. 11export function appendEmissions(file: RegisterFile, emissions: readonly WaveEmission[]): void {
   12. 12 const engine = file.registers.engine;
   13. 13 for (const emission of emissions) {
   14. 14 const tuple: WaveTuple = { ...emission, offset: engine.base + engine.window.length };↑ the new record gets the next free number
   15. 15 engine.window.push(tuple);↑ it is added at the end of the log
   16. 16 recordTransition(file, "engine", "LOG", "append", {↑ the change is written into the journal
   17. 17 offset: tuple.offset,
   18. 18 kind: tuple.kind
   19. 19 });
   20. 20 }
   21. 21}

   AGPL-3.0-onlyThe Lab's demonstration environment, as this fragment ran it (build 043cc8b). The code may change, and may differ from the code of a working machine.

   Nest VM core, incubated in the CoAgnes garden · build 043cc8b (2026-09-21) · this file last changed in f36e70d (2026-08-18)

when the engine took #27

1. 145The engine takes #27ENGINE.CURSOR · propagate

   a wave is settlingengine: working on #27membrane: waiting at #25

   1. #0a listener
   2. #1a doer
   3. #2listener: the charter
   4. #3doer: the author
   5. #4listener: charter seen
   6. #5listener: blueprint seen
   7. #6doer: the planner
   8. #7listener: assess · charter
   9. #8listener: assess · result
   10. #9doer: the evaluator
   11. #10the charter wanted
   12. #11the blueprint
   13. #12readiness
   14. #13readiness
   15. #14a request: a charter
   16. #15the charter proposed
   17. #16the charter defined
   18. #17readiness
   19. #18readiness
   20. #19a request: a Cell
   21. #20the seed
   22. #21the Cell is open
   23. #22inner listener
   24. #23inner doer
   25. #24the Cell's context
   26. #25return listenermembrane
   27. #26return doer
   28. #27the return addressengine · working
   29. ·end of the log

   What	before		after
   pointer — the next record to take	#27	→	#28

   The engine moves on to #27, the return address, and the machine reacts to it.

   Where it happens takeNextTuple()Vol. 02 §4.1

   The engine's step: take the record under its pointer and move the pointer on — or stop, if the pointer has reached the end.

   Specification

   Vol. 02 §4.1

   Code

   takeNextTuple() in core/registers/take-next-tuple.ts, line 15: at the end of the log, the engine stops

   Journal

   #27 · ENGINE.CURSOR · propagate · offset: 27 · by engine

   Picture

   pointer — the next record to take: #27 → #28

   1. 1// ENGINE.CURSOR advance (Vol. 02 §4.1) — the machine's instruction pointer:
   2. 2// returns the tuple at the cursor and moves it forward exactly once, or null
   3. 3// at quiescence. Advancing IS the context switch: the ambient wave context
   4. 4// moves to the propagated tuple in the same movement, so every transition
   5. 5// journalled during its propagation is attributed to it — the cube's spine.
   6. 6// The cursor never rewinds.
   7. 7
   8. 8import type { WaveTuple } from "../wave/gate";
   9. 9import type { RegisterFile } from "./register-file";
   10. 10import { recordTransition } from "./record-transition";
   11. 11import { setDriver, setWaveContext } from "./set-wave-context";
   12. 12
   13. 13export function takeNextTuple(file: RegisterFile): WaveTuple | null {
   14. 14 const engine = file.registers.engine;
   15. 15 if (engine.cursor >= engine.base + engine.window.length) return null;↑ at the end of the log, the engine stops
   16. 16 const tuple = engine.window[engine.cursor - engine.base];
   17. 17 engine.cursor += 1;↑ the engine's pointer moves on by one
   18. 18 setWaveContext(file, { offset: tuple.offset, phase: "propagate" });
   19. 19 setDriver(file, "engine");
   20. 20 recordTransition(file, "engine", "ENGINE.CURSOR", "propagate", { offset: tuple.offset });↑ the change is written into the journal
   21. 21 return tuple;
   22. 22}

   AGPL-3.0-onlyThe Lab's demonstration environment, as this fragment ran it (build 043cc8b). The code may change, and may differ from the code of a working machine.

   Nest VM core, incubated in the CoAgnes garden · build 043cc8b (2026-09-21) · this file last changed in 6730f58 (2026-09-13)

2. 146The return listener opens a laneCLEWS · open-clew

   a wave is settlingengine: working on #27membrane: waiting at #25

   1. #0a listener
   2. #1a doer
   3. #2listener: the charter
   4. #3doer: the author
   5. #4listener: charter seen
   6. #5listener: blueprint seen
   7. #6doer: the planner
   8. #7listener: assess · charter
   9. #8listener: assess · result
   10. #9doer: the evaluator
   11. #10the charter wanted
   12. #11the blueprint
   13. #12readiness
   14. #13readiness
   15. #14a request: a charter
   16. #15the charter proposed
   17. #16the charter defined
   18. #17readiness
   19. #18readiness
   20. #19a request: a Cell
   21. #20the seed
   22. #21the Cell is open
   23. #22inner listener
   24. #23inner doer
   25. #24the Cell's context
   26. #25return listenermembrane
   27. #26return doer
   28. #27the return addressengine · working
   29. ·end of the log

   What	before		after
   lane · this session	—	→	open

   The return listener hears return.declared for cell@20, so it opens a lane. The address came after the listener, so it reaches it: a fact is heard only by listeners that existed before it.

   Where it happens ensureClew()Vol. 02 §4.2 · Vol. 03 §5.1

   Opens a lane in a listener for a new key — the first time a fact with that key reaches it.

   Specification

   Vol. 02 §4.2 · Vol. 03 §5.1

   Code

   ensureClew() in core/registers/ensure-clew.ts, line 15: a new lane is opened for this key

   Journal

   #27 · CLEWS · open-clew · key: fragment-one-cell · by knot:return.cell-20.gate

   Picture

   lane · this session: — → open

   1. 1// CLEWS lane creation (Vol. 02 §4.2): a clew is created lazily on the first
   2. 2// tuple of its key — parallel keys wind independent understanding (Vol. 05
   3. 3// §2, Vol. 03 §5.1). Creation is a transition (journalled); an existing lane
   4. 4// is a read and passes through silently.
   5. 5
   6. 6import type { ClewHandle, ClewRegisters } from "./topology-registers";
   7. 7import { recordTransition } from "./record-transition";
   8. 8
   9. 9export function ensureClew(clew: ClewHandle, init: () => ClewRegisters): ClewRegisters {
   10. 10 const lanes = clew.region.clews.get(clew.knotId);
   11. 11 if (!lanes) throw new Error(`Clew bank missing for knot '${clew.knotId}' — registration must precede facts (Vol. 02 §5.1).`);
   12. 12 let registers = lanes.get(clew.key);
   13. 13 if (!registers) {
   14. 14 registers = init();
   15. 15 lanes.set(clew.key, registers);↑ a new lane is opened for this key
   16. 16 recordTransition(clew.file, `topology:${clew.region.regionId}/clew:${clew.knotId}`, "CLEWS", "open-clew", {↑ the change is written into the journal
   17. 17 key: clew.key
   18. 18 });
   19. 19 }
   20. 20 return registers;
   21. 21}

   AGPL-3.0-onlyThe Lab's demonstration environment, as this fragment ran it (build 043cc8b). The code may change, and may differ from the code of a working machine.

   Nest VM core, incubated in the CoAgnes garden · build 043cc8b (2026-09-21) · this file last changed in f36e70d (2026-08-18)

3. 147The address is keptCOLLECTED · collect

   a wave is settlingengine: working on #27membrane: waiting at #25

   1. #0a listener
   2. #1a doer
   3. #2listener: the charter
   4. #3doer: the author
   5. #4listener: charter seen
   6. #5listener: blueprint seen
   7. #6doer: the planner
   8. #7listener: assess · charter
   9. #8listener: assess · result
   10. #9doer: the evaluator
   11. #10the charter wanted
   12. #11the blueprint
   13. #12readiness
   14. #13readiness
   15. #14a request: a charter
   16. #15the charter proposed
   17. #16the charter defined
   18. #17readiness
   19. #18readiness
   20. #19a request: a Cell
   21. #20the seed
   22. #21the Cell is open
   23. #22inner listener
   24. #23inner doer
   25. #24the Cell's context
   26. #25return listenermembrane
   27. #26return doer
   28. #27the return addressengine · working
   29. ·end of the log

   What	before		after
   lane · this session · slot address	empty	→	cellRef = “cell@20” · slot = {"bind":"note.echo","knot":"note.gate"} · as = {"factType":"note.given","field":"text","where":[]} · mode = “answer” · exportType = “knowledge.l1.accepted” · session = “fragment-one-cell” · seat = “l1.seeking” · level = “l1.seeking”

   The address goes into the slot address: into the slot of note.echo and note.gate, as a note.given. The other slot is empty, so the listener is not ready: it holds the address and waits.

   Where it happens collectDeterministicSlot()Vol. 02 §4.4 · Vol. 05 §3.3

   Fills a slot of a listener with a value it heard.

   Specification

   Vol. 02 §4.4 · Vol. 05 §3.3

   Code

   collectDeterministicSlot() in core/registers/collect-deterministic-slot.ts, line 20: the slot is filled

   Journal

   #27 · COLLECTED · collect · key: fragment-one-cell, slot: address, reduce: latest · by knot:return.cell-20.gate

   Picture

   lane · this session · slot address: empty → cellRef = “cell@20” · slot = {"bind":"note.echo","knot":"note.gate"} · as = {"factType":"note.given","field":"text","where":[]} · mode = “answer” · exportType = “knowledge.l1.accepted” · session = “fragment-one-cell” · seat = “l1.seeking” · level = “l1.seeking”

   1. 1// COLLECTED write (Vol. 02 §4.4, Vol. 05 §3.3): the deterministic knot's
   2. 2// slot fills — `append` accumulates an array, otherwise the newest value
   3. 3// stands. The condition never runs here; this op records the landing.
   4. 4
   5. 5import type { DeterministicClewRegisters, ClewHandle } from "./topology-registers";
   6. 6import { recordTransition } from "./record-transition";
   7. 7
   8. 8export function collectDeterministicSlot(
   9. 9 clew: ClewHandle,
   10. 10 registers: DeterministicClewRegisters,
   11. 11 slot: string,
   12. 12 reduce: string,
   13. 13 value: unknown
   14. 14): void {
   15. 15 if (reduce === "append") {
   16. 16 const existing = registers.collected.get(slot);
   17. 17 if (Array.isArray(existing)) existing.push(value);
   18. 18 else registers.collected.set(slot, [value]);
   19. 19 } else {
   20. 20 registers.collected.set(slot, value);↑ the slot is filled
   21. 21 }
   22. 22 recordTransition(clew.file, `topology:${clew.region.regionId}/clew:${clew.knotId}`, "COLLECTED", "collect", {↑ the change is written into the journal
   23. 23 key: clew.key,
   24. 24 slot,
   25. 25 reduce
   26. 26 });
   27. 27}

   AGPL-3.0-onlyThe Lab's demonstration environment, as this fragment ran it (build 043cc8b). The code may change, and may differ from the code of a working machine.

   Nest VM core, incubated in the CoAgnes garden · build 043cc8b (2026-09-21) · this file last changed in f36e70d (2026-08-18)

when the membrane passed #27

1. 150The membrane passes #27MEMBRANE.CURSOR · sweep

   a wave is settlingengine: at the endmembrane: passing #27

   1. #0a listener
   2. #1a doer
   3. #2listener: the charter
   4. #3doer: the author
   5. #4listener: charter seen
   6. #5listener: blueprint seen
   7. #6doer: the planner
   8. #7listener: assess · charter
   9. #8listener: assess · result
   10. #9doer: the evaluator
   11. #10the charter wanted
   12. #11the blueprint
   13. #12readiness
   14. #13readiness
   15. #14a request: a charter
   16. #15the charter proposed
   17. #16the charter defined
   18. #17readiness
   19. #18readiness
   20. #19a request: a Cell
   21. #20the seed
   22. #21the Cell is open
   23. #22inner listener
   24. #23inner doer
   25. #24the Cell's context
   26. #25return listener
   27. #26return doer
   28. #27the return addressmembrane · passing
   29. ·end of the logengine

   What	before		after
   pointer — the next record to pass	#27	→	#28

   #27 asks nothing of the world, so the membrane's pointer simply moves on.

   Where it happens sweepNextTuple()Vol. 02 §4.6 · Vol. 07 §3

   The membrane's step: pass over the record under its pointer and move the pointer on — exactly once per record.

   Specification

   Vol. 02 §4.6 · Vol. 07 §3

   Code

   sweepNextTuple() in core/registers/sweep-next-tuple.ts, line 16: the membrane's pointer moves on by one

   Journal

   #27 · MEMBRANE.CURSOR · sweep · offset: 27 · by membrane

   Picture

   pointer — the next record to pass: #27 → #28

   1. 1// MEMBRANE.CURSOR advance (Vol. 02 §4.6, Vol. 07 §3): the membrane's own
   2. 2// reading of the one log — the second reception of one publication, never a
   3. 3// second truth. The cursor advances exactly once per offset per machine:
   4. 4// the exactly-once discharge guarantee lives in this movement.
   5. 5
   6. 6import type { WaveTuple } from "../wave/gate";
   7. 7import type { RegisterFile } from "./register-file";
   8. 8import { recordTransition } from "./record-transition";
   9. 9import { setDriver, setWaveContext } from "./set-wave-context";
   10. 10
   11. 11export function sweepNextTuple(file: RegisterFile): WaveTuple | null {
   12. 12 const engine = file.registers.engine;
   13. 13 const membrane = file.registers.membrane;
   14. 14 if (membrane.cursor >= engine.base + engine.window.length) return null;
   15. 15 const tuple = engine.window[membrane.cursor - engine.base];
   16. 16 membrane.cursor += 1;↑ the membrane's pointer moves on by one
   17. 17 setWaveContext(file, { offset: tuple.offset, phase: "sweep" });
   18. 18 setDriver(file, "membrane");
   19. 19 recordTransition(file, "membrane", "MEMBRANE.CURSOR", "sweep", { offset: tuple.offset });↑ the change is written into the journal
   20. 20 return tuple;
   21. 21}

   AGPL-3.0-onlyThe Lab's demonstration environment, as this fragment ran it (build 043cc8b). The code may change, and may differ from the code of a working machine.

   Nest VM core, incubated in the CoAgnes garden · build 043cc8b (2026-09-21) · this file last changed in 6730f58 (2026-09-13)