a wave is settlingengine working on #39membrane waiting at #36

Wave 5 · The return · record #39sys.knot.ready

#39 · the return is ready

The return doer writes its one fact in one step — a request to present the answer again, #40.

Came fromthe machineThe machine wrote it while the engine took #38: the return listener had both its slots. step 210

Read as

when the engine took #39

  1. 211The engine takes #39ENGINE.CURSOR · propagate

    a wave is settlingengine: working on #39membrane: waiting at #36

    The log
    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 address
    29. #28the person's words
    30. #29readiness
    31. #30the private result
    32. #31the result, marked
    33. #32readiness
    34. #33a request: assess
    35. #34assessment proposed
    36. #35the Cell assessed
    37. #36the decisionmembrane
    38. #37the Cell sealed
    39. #38the export
    40. #39readinessengine · working
    41. end of the log
    The engine
    Whatbeforeafter
    pointer — the next record to take#39#40

    The engine moves on to #39 — the return listener's readiness.

    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
    #39 · ENGINE.CURSOR · propagate · offset: 39 · by engine
    Picture
    pointer — the next record to take: #39 → #40
    core/registers/take-next-tuple.ts · build 043cc8b
    1. // ENGINE.CURSOR advance (Vol. 02 §4.1) — the machine's instruction pointer:
    2. // returns the tuple at the cursor and moves it forward exactly once, or null
    3. // at quiescence. Advancing IS the context switch: the ambient wave context
    4. // moves to the propagated tuple in the same movement, so every transition
    5. // journalled during its propagation is attributed to it — the cube's spine.
    6. // The cursor never rewinds.
    7. import type { WaveTuple } from "../wave/gate";
    8. import type { RegisterFile } from "./register-file";
    9. import { recordTransition } from "./record-transition";
    10. import { setDriver, setWaveContext } from "./set-wave-context";
    11. export function takeNextTuple(file: RegisterFile): WaveTuple | null {
    12. const engine = file.registers.engine;
    13. if (engine.cursor >= engine.base + engine.window.length) return null;↑ at the end of the log, the engine stops
    14. const tuple = engine.window[engine.cursor - engine.base];
    15. engine.cursor += 1;↑ the engine's pointer moves on by one
    16. setWaveContext(file, { offset: tuple.offset, phase: "propagate" });
    17. setDriver(file, "engine");
    18. recordTransition(file, "engine", "ENGINE.CURSOR", "propagate", { offset: tuple.offset });↑ the change is written into the journal
    19. return tuple;
    20. }

    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. 212The return doer writes #40 — in one stepLOG · append

    a wave is settlingengine: working on #39membrane: waiting at #36

    The log
    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 address
    29. #28the person's words
    30. #29readiness
    31. #30the private result
    32. #31the result, marked
    33. #32readiness
    34. #33a request: assess
    35. #34assessment proposed
    36. #35the Cell assessed
    37. #36the decisionmembrane
    38. #37the Cell sealed
    39. #38the export
    40. #39readinessengine · working
    41. #40a request: present againnew
    42. end of the log
    The log
    Whatbeforeafter
    records in the log4041
    #40—a request: present again · represent.requested

    The return doer has no rendezvous, no scope and no intention: its listener is ready, so it writes its one fact — #40, a request to present the answer again at the address.

    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
    #39 · LOG · append · offset: 40, kind: domain.fact · by engine
    Picture
    records in the log: 40 → 41
    core/registers/append-emissions.ts · build 043cc8b
    1. // The one LOG writer (Vol. 02 §4.1, Vol. 03 §1): emissions become tuples by
    2. // receiving the next dense absolute offset — `base + window.length` — and
    3. // nothing else ever grows the log. Each append is journalled under the
    4. // ambient context, so a batch born of a propagated tuple carries that
    5. // tuple's offset as its cause — the cube's provenance line (ADR-002).
    6. import type { WaveEmission, WaveTuple } from "../wave/gate";
    7. import type { RegisterFile } from "./register-file";
    8. import { recordTransition } from "./record-transition";
    9. export function appendEmissions(file: RegisterFile, emissions: readonly WaveEmission[]): void {
    10. const engine = file.registers.engine;
    11. for (const emission of emissions) {
    12. const tuple: WaveTuple = { ...emission, offset: engine.base + engine.window.length };↑ the new record gets the next free number
    13. engine.window.push(tuple);↑ it is added at the end of the log
    14. recordTransition(file, "engine", "LOG", "append", {↑ the change is written into the journal
    15. offset: tuple.offset,
    16. kind: tuple.kind
    17. });
    18. }
    19. }

    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 #39

  1. 217The membrane passes #39MEMBRANE.CURSOR · sweep

    a wave is settlingengine: at the endmembrane: passing #39

    The log
    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 address
    29. #28the person's words
    30. #29readiness
    31. #30the private result
    32. #31the result, marked
    33. #32readiness
    34. #33a request: assess
    35. #34assessment proposed
    36. #35the Cell assessed
    37. #36the decision
    38. #37the Cell sealed
    39. #38the export
    40. #39readinessmembrane · passing
    41. #40a request: present again
    42. end of the logengine
    The membrane
    Whatbeforeafter
    pointer — the next record to pass#39#40

    #39 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
    #39 · MEMBRANE.CURSOR · sweep · offset: 39 · by membrane
    Picture
    pointer — the next record to pass: #39 → #40
    core/registers/sweep-next-tuple.ts · build 043cc8b
    1. // MEMBRANE.CURSOR advance (Vol. 02 §4.6, Vol. 07 §3): the membrane's own
    2. // reading of the one log — the second reception of one publication, never a
    3. // second truth. The cursor advances exactly once per offset per machine:
    4. // the exactly-once discharge guarantee lives in this movement.
    5. import type { WaveTuple } from "../wave/gate";
    6. import type { RegisterFile } from "./register-file";
    7. import { recordTransition } from "./record-transition";
    8. import { setDriver, setWaveContext } from "./set-wave-context";
    9. export function sweepNextTuple(file: RegisterFile): WaveTuple | null {
    10. const engine = file.registers.engine;
    11. const membrane = file.registers.membrane;
    12. if (membrane.cursor >= engine.base + engine.window.length) return null;
    13. const tuple = engine.window[membrane.cursor - engine.base];
    14. membrane.cursor += 1;↑ the membrane's pointer moves on by one
    15. setWaveContext(file, { offset: tuple.offset, phase: "sweep" });
    16. setDriver(file, "membrane");
    17. recordTransition(file, "membrane", "MEMBRANE.CURSOR", "sweep", { offset: tuple.offset });↑ the change is written into the journal
    18. return tuple;
    19. }

    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)

Choose a step in the stack — or press →.

A listener's readiness

The machine's own record that a listener's condition came true. It names the listener and keeps what the listener understood at that moment — its slots, taken before they are emptied, and written before any doer acts.

#39sys.knot.ready the machine

envelope
offset39Its place in the log — the only address a record has. The engine gives it when the record is added, the next free number, and it never changes.
kindsys.knot.readyWhich of the four kinds of record the machine knows. The kind decides what the payload holds.
keyfragment-one-cellThe lane of the fact that made the listener ready.
payload
knotIdreturn.cell-20.gateThe listener that is ready.
payload.understanding
addresscellRef · slot · as · mode · exportType · session · seat · levelWhat the return listener understood, first: where to return the answer, and as what.
exportcellRef · charterRef · assessmentOffset · reviewOffset · result…and then: the Cell's accepted answer, with the charter, the assessment and the review it rests on.

end · #39

In the specificationVol. 03 §1Vol. 03 §2Vol. 03 §5Vol. 04 §2.3

Names it shares with other records

The record as the machine keeps it
{
 "offset": 39,
 "kind": "sys.knot.ready",
 "key": "fragment-one-cell",
 "payload": {
  "knotId": "return.cell-20.gate",
  "understanding": {
   "address": {
    "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"
   },
   "export": {
    "cellRef": "cell@20",
    "charterRef": "charter@15",
    "assessmentOffset": 34,
    "reviewOffset": 36,
    "result": {
     "text": "A Cell is a bounded study the machine opens when a slot needs more than a fact: it has its own charter, its own knots and binds, and a result that is assessed and reviewed before anything returns."
    }
   }
  }
 }
}