The recorded exchange: clock, signal and three records on one arena, with one evolution #
Category: 7-SigmaLayer (the record layer — the common arena of the clock-and-echo programme). BACKLOG #186 (out of #39; the fourth of #183–#189, the price driver).
#183 built the signal (a two-site hop on FieldArena 2 2), #185 the clock (ClockArena K). This
file puts them on one arena with one evolution and adds the three record registers the
experiment needs — emission at A, reception at B, return at A — each written by the record
mechanism of ShearWitness.lean: a pointer translated by shearAmt 2 b from the ready arc into the
pointer arc of the bit b it reads. A register is written on the crossing of its readout time, by
the bit read off the exchange state at that time; the hop is switched on at t = 0, the
apparatus is prepared at t = −1.
XArena K = FieldArena 2 2 × ClockArena K × (Fin 3 → KTorus);hopOn,arrived,readTime,readSite,readBit(the occupancy weight of a site, thresholded at1/2, measurable bymeasurable_momentMap);xEvolve J ħ T s t— the joint two-time propagator;xEvolve_self, ★★xEvolve_comp— the two-time law holds on the common arena: the bit a register reads is the exchange state at its readout time, which the group law of the hop makes independent of where the propagator is cut;measurable_xEvolve; ★xEvolve_measurePreserving— Liouville (Fubini–Study × Haar × Haar) is preserved: it is a dynamics;XReady,xPrep b c r— the ready preparation with messageb;register_before, ★★register_written— each register is written with the message, emission at0, reception atτ_hop, return at2 τ_hop, from the actual transfer (arenaFlow_hopTime,arenaFlow_roundTrip) and nothing else;register_frozen;recordProtocol i— each register is aMeasurementProtocol,recordProtocol_pointerInvariant, ★record_persiststhrough the corpus'srecord_persists_on_interval;- ★★
reception_depends_on_message,return_depends_on_message— demonstrated influence: two preparations differing only in the message (msgConfig_siteB) leave the reception register, and the return register, in disjoint pointer arcs; Occurrence,emission,reception,returnOcc,eventOf— occurrences with their register, site, time and message, and the forgetful map toCV.RecordEvent, whose period label is the tick count of the physical clock in the arena at the occurrence time (eventOf_emission,eventOf_reception,eventOf_returnunder the stated calibrationT = τ_hop);- ★★
causal_chain—emission ⪯ reception ⪯ returnunderCausalPrecedeson the coupling graph{(A, B)}, andemission ⪯ returnby the corpus's transitivity; recordEvents,recordPattern, ★factorsThrough_recordEvents— the record predicates factor through a macroscopic projection, the pattern projection ofMacroProjection.lean;- ★★★
recorded_exchange— the package.
The two clocks, identified explicitly #
RecordEvent.time is a period index; the clock reads a tick count. They coincide here by a
stated modelling choice: the clock period is the hop time, T = τ_hop, so emission, reception
and return fall at ticks 0, 1, 2 (tickCount_at_period). With another period the same
occurrences carry other labels; nothing identifies the two clocks dynamically.
Honest scope #
- ⚠️ The readout times and the switch-on are a schedule, a modelling input indexed by
t_Σ, as in #185. The writes are triggered by the schedule reading the exchange state; a dynamical trigger is not built. - ⚠️
CausalPrecedesis permitted influence on an assumed graph; the demonstrated influence isreception_depends_on_message. Both are proved; neither is inferred from the other. - The bit is read by thresholding an occupancy weight at
1/2. At the readout times the exchange state is a basis ray, so the weight is0or1and the threshold is never close; between them it is not read. - No metric, no volume element on the event order, no universal
c: the scoping note's §8 stands.
References: specs/BACKLOG.md #186, #183, #185, #187, #39; CV/SignalExchange.lean,
RecordLayer/RecordClock.lean, CV/RecordCausalOrder.lean (RecordEvent, CausalPrecedes),
RecordLayer/MacroProjection.lean (patternProjection, factorsThrough_patternMap),
RecordLayer/ShearWitness.lean (the arcs and shearAmt), RecordLayer/RecordPersistence.lean.
The common arena #
The experiment's arena: the exchange, the clock, and three record registers
(0 emission at A, 1 reception at B, 2 return at A).
Equations
- CSD.RecordLayer.XArena K = (CSD.CV.FieldArena 2 2 × CSD.RecordLayer.ClockArena K × (Fin 3 → CSD.LF4.KTorus))
Instances For
The hop coupling is switched on at t = 0: the exchange has run for hopOn u by time u.
Equations
- CSD.RecordLayer.hopOn u = max u 0
Instances For
1 once the readout time τ has arrived, 0 before.
Instances For
The readout times: emission at 0, reception at τ_hop, return at 2 τ_hop.
Equations
- CSD.RecordLayer.readTime J ħ = ![0, CSD.CV.hopTime J ħ, CSD.CV.roundTrip J ħ]
Instances For
The site each register reads: A, B, A.
Instances For
The one-excitation configuration of a site.
Instances For
The bit read off a ray at a configuration: its occupancy weight thresholded at 1/2.
Equations
- CSD.RecordLayer.readBit c p = if 1 / 2 ≤ Projectivization.momentMap p c then 1 else 0
Instances For
The arena kick is the unitary action #
The joint propagator #
The bit register i reads: the occupancy of its site in the exchange state at its readout
time, when the propagator starts at s.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The joint two-time propagator: the hop runs from switch-on, the clock runs on its schedule,
and register i is translated by shearAmt 2 (bit) on the crossing of its readout time, the bit
being read off the exchange state at that time.
Equations
- One or more equations did not get rendered due to their size.
Instances For
The bit read at the readout time does not depend on where the propagator is cut.
★★ The two-time composition law on the common arena.
The exchange factor preserves the Fubini–Study measure at every reference point.
★ The joint propagator preserves Liouville measure — Fubini–Study on the exchange, Haar on the clock and the registers — for every reference point of the Fubini–Study measure: it is a dynamics. The register shifts depend on the exchange state, so this is a skew product.
The ready preparation and what the registers read #
The ready preparation: clock ready, all three registers in the ready arc.
Equations
- CSD.RecordLayer.XReady K = {x : CSD.RecordLayer.XArena K | x.2.1 ∈ CSD.RecordLayer.ClockReady K ∧ ∀ (i : Fin 3), x.2.2 i ∈ CSD.RecordLayer.readyArc 2}
Instances For
The preparation with message b: the exchange at the message point, clock and registers as
given.
Equations
- CSD.RecordLayer.xPrep b c r = (CSD.CV.msgPoint b, c, r)
Instances For
The occupancy weight of a configuration at a message point is 1 at the message's
configuration and 0 elsewhere.
The vacuum does not move: message 0's exchange point is fixed by the hop.
At A, the message point reads its message.
The records #
A ready pointer shifted by shearAmt K i displays outcome i.
★★ Each register is written with the message from its readout time on: emission at 0,
reception at τ_hop, return at 2 τ_hop.
Each register is a measurement protocol; the records persist #
Register i as a MeasurementProtocol with two outcomes (the bit), prepared at −1, read
out at its readout time, with record lifetime τR.
Equations
- One or more equations did not get rendered due to their size.
Instances For
★ The records persist from the readout time through the record lifetime — by the corpus's
record_persists_on_interval, applied to recordProtocol i.
Demonstrated influence: the records depend on the message #
★★ The reception record depends on the message: two preparations identical except for the
occupancy of A (msgConfig_siteB) leave the reception register in disjoint pointer arcs.
The return record depends on the message in the same way.
Occurrences and the forgetful map to record events #
An occurrence along the constructed evolution: which register writes, at which site, at
which time, recording which message. Richer than CV.RecordEvent, which keeps region and period
only.
- register : Fin 3
The register that writes.
- site : Fin 2
The site of the write.
- time : ℝ
The ontic time of the write.
- message : Fin 2
The message the write records.
Instances For
The emission of message b at A, time 0.
Equations
- CSD.RecordLayer.emission b = { register := 0, site := 0, time := 0, message := b }
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The reception of message b at B, time τ_hop.
Equations
- CSD.RecordLayer.reception J ħ b = { register := 1, site := 1, time := CSD.CV.hopTime J ħ, message := b }
Instances For
The return of message b at A, time 2 τ_hop.
Equations
- CSD.RecordLayer.returnOcc J ħ b = { register := 2, site := 0, time := CSD.CV.roundTrip J ħ, message := b }
Instances For
The forgetful map to CV.RecordEvent: the region is the site, and the period label is the
tick count of the physical clock in the arena at the occurrence time.
Equations
- CSD.RecordLayer.eventOf J ħ T x o = { region := {o.site}, time := CSD.RecordLayer.tickCount (CSD.RecordLayer.xEvolve J ħ T (-1) o.time x).2.1 }
Instances For
The clock in the arena, run from −1, has the slots of the clock run from 0.
★★ The causal chain: emission ⪯ reception ⪯ return under CausalPrecedes on the hop
graph, and emission ⪯ return by the corpus's transitivity.
The record predicates factor through a macroscopic projection #
The record events: register i displays bit j.
Equations
- CSD.RecordLayer.recordEvents j i = {x : CSD.RecordLayer.XArena K | x.2.2 i ∈ CSD.RecordLayer.pointerArc 2 j}
Instances For
The macroscopic coordinate of the experiment's records: the pattern projection of the three
"register i displays j" events.
Equations
Instances For
★ Every record predicate factors through the macroscopic projection.
The package #
★★★ The recorded exchange. On the common arena with its one two-time, measure-preserving
evolution: from the ready preparation with message b, the three registers are written with b
at 0, τ_hop, 2 τ_hop and persist; the reception register distinguishes the two messages;
under the calibration T = τ_hop the occurrences map to record events at periods 0, 1, 2 that
form the chain emission ⪯ reception ⪯ return on the hop graph; and the record predicates factor
through the pattern projection.