# Logic Principles of the Tripartite Synapse Model

These are the principles that govern the system's logic — not the syntax in which it is
expressed, but the reasoning that shapes every variable, every behavior, and every
transition. They are organized into ten categories, from the most foundational to the
most emergent. The final category shows how principles that are stated entirely in local
terms necessarily produce a holistic system — a whole that no part represents but that
every part participates in.

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## I. Resource and Conservation

**Nothing is free.** Every behavior consumes a resource. There is no operation in the
system that does not draw something down. This is not a constraint added on top of the
logic — it is the foundation. Selectivity, competition, and forgetting all emerge from
the single fact that resources are finite.

**Resources are redistributed, not created.** The total pool is bounded by an external
ceiling. Within it, the system only moves resources around — from one synapse to another,
from a dismantled structure back into the pool. No internal process manufactures capacity;
it only reallocates. Learning is therefore always at the expense of something else.

**Two distinct resources, two distinct conservation laws.** Energy is a flow — consumed
and replenished continuously, gone after use. Material is a stock — incorporated into
structures and recovered when structures are dismantled. They have different sources,
different timescales, and different recovery dynamics. A behavior can be energetically
affordable yet materially limited, or vice versa. Conflating them would destroy both
conservation laws; keeping them separate is what makes resource accounting honest.

**Every economy has a single capped root.** Each resource traces back to one producer
with a hard ceiling — the astrocyte cell body for synaptic energy, the soma for neuronal
material. Everything downstream competes for shares of that capped production. The ceiling
is the ultimate arbiter of how much the system can do, and it is set outside the system.

**Conservation makes one synapse's gain another's loss.** Because resources are shared and
finite, strengthening one site necessarily reduces what is available elsewhere. This
coupling is not designed — it is the automatic consequence of drawing from a common pool.
Depression at one synapse returns resources that partially fund potentiation at another.

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## II. Time and Scope

**Behavior and structural change occupy separate scopes.** Fast behavior happens in DAY;
permanent change happens in NIGHT. This separation prevents transient activity from
directly rewriting architecture — otherwise every noise spike would remodel the system.
The scope boundary is what makes the system both responsive and stable.

**DAY accumulates evidence; NIGHT acts on it.** No permanent decision is made in the
moment. DAY only gathers traces. NIGHT reads the aggregated evidence and commits. The
system always defers commitment to a consolidation phase that operates on accumulated
evidence, never on a single instant.

**Timescale is meaning.** Fast traces decay in milliseconds, tags in hours, structures
over days. The decay constant of a variable is not a parameter — it is what the variable
means. A fast-decaying variable is a momentary signal; a slow-decaying one is a
commitment. Putting two timescales in one variable destroys both meanings — which is why
every quantity that carries both a momentary and a lasting role must be split into two
variables with two decay constants.

**Time windows are enforced by chemistry, not by clocks.** The system never checks a
timer. Coincidence windows emerge from the competition between accumulation and decay. A
signal must arrive while a trace is still elevated; the window opens when the trace crosses
threshold and closes when it decays below it. Timing is a consequence of dynamics, never
an explicit rule.

**The rest period is the execution window.** DAY fills the system with evidence but
commits nothing. NIGHT executes — writing structure and budget capacity, replenishing
pools, clearing traces. Neither scope alone suffices: DAY without NIGHT produces learning
that cannot consolidate; NIGHT without DAY produces replenishment with nothing to
consolidate. The alternation is not incidental — it is architectural.

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## III. Capacity and Occupancy

**NIGHT builds containers; DAY fills them.** Every slow variable is a capacity — a ceiling
on what behavior can achieve. NIGHT changes the ceiling; DAY operates within it. The two
never do each other's job: NIGHT never places a receptor, DAY never builds a slot. This
single principle organizes the entire architecture.

**Short-term change is occupancy; long-term change is capacity.** Filling a container is
fast and reversible; resizing it is slow and persistent. The same physical quantity —
receptor count, vesicle count, fuel level — has a fast component (how full) and a slow
component (how big), governed by entirely different processes at entirely different scopes.

**Two capacities, two drives, one pool.** Structure is the capacity for strength — how
powerfully each behavior can act. Budget capacity is the capacity for endurance — how long
behavior can be sustained. Both are ceilings built at NIGHT and filled competitively at
DAY. Both draw from the same finite material and energy, so strength and endurance compete:
investing endurance somewhere cannot strengthen elsewhere.

**A ceiling is never free, even during DAY.** Building a ceiling at NIGHT costs material
and energy; filling it at DAY costs a competitive share of a shared resource. Structure
must be filled by winning occupancy; budget capacity must be filled by winning shared fuel.
A high ceiling of either kind makes a large standing claim that the component can satisfy
only if it out-competes its neighbors. Capacity that cannot be filled is capacity wasted.

**Structure shapes form, not just maximum.** Structure does not merely set a ceiling — it
shapes the transfer function between input and output at every moment. Tightly clustered
calcium channels make each spike more reliably coupled to release; more anchoring slots
make each glutamate pulse more faithfully converted to current; tonic D-serine keeps the
gate chronically primed. The architecture conditions the quality of behavior continuously,
not just its peak.

---

## IV. The Timescale Ladder

This is the spine the other principles hang from. The system's quantities occupy four nested
tiers, and timescale is not incidental to them — it *is* what distinguishes them.

**Four tiers, by timescale.** FAST traces (milliseconds to seconds) — the residual calcium, the
synaptic current, the immediate response. MEDIUM occupancy and evidence (seconds to minutes) —
the filled receptor surface and channel coupling, the accumulating possible-tag, the endurance
need. The SLOW tag (hours) — the validated bridge to consolidation. PERSISTENT capacity
(written only at NIGHT, drifting over days) — the structure and budget ceilings. Each tier
decays on its own timescale, and that decay constant is the tier's meaning: a fast-decaying
quantity is a momentary signal, a slow one a commitment, and a non-decaying one a capacity.

**The tiers are a ladder, not just four speeds.** Each rung's output is the next rung's input,
and the coupling runs in two directions at once.

**Capacity flows downward — each slower tier sets the ceiling for the faster one below it.**
Persistent structure bounds how far medium occupancy can fill; medium occupancy (current
coupling, current receptor surface) bounds how strongly fast behavior can act. A behavior never
acts beyond the occupancy currently filled, and occupancy never fills beyond the structure built
last night. The ceiling at every level was set by the level above, on a slower timescale.

**Evidence flows upward — each faster tier accumulates toward the slower one above it.** Fast
traces accumulate into medium evidence (possible-tag and endurance-need); medium evidence
bridges, on coincidence with validation, into the slow tag; the slow tag commits, at NIGHT, into
persistent capacity. Each tier is the evidence from which the next slower tier is built, and
nothing reaches a slower tier without having accumulated through the faster ones first.

**Both pathways are instances of the climb.** The strength pathway (fast trace → medium
possible-tag → slow tag → persistent structure) and the endurance pathway (fast trace → medium
endurance-need → persistent budget ceiling) are the same upward flow of evidence, differing only
in what validates the climb — associative dopamine for strength, homeostatic fuel-shortfall for
endurance. And both ceilings they build then flow back downward as the bounds the next day's
behavior runs within.

**This single image contains the model's whole logic.** Capacity-versus-occupancy is the
downward flow; the two evidence streams are the upward flow; the DAY/NIGHT split is just where
the ladder is climbed (evidence accumulates by DAY) versus where it is committed (capacity is
written at NIGHT). The functional groups enact the ladder: ADJUST and BEHAVE read capacity
downward, TRACE accumulates evidence upward, and NIGHT commits the top of the upward flow into
the source of the downward flow. To understand the system is to see that it is a four-rung ladder
with capacity descending and evidence ascending, turning once per DAY/NIGHT cycle.

**The ladder governs pools as well as traces — and a pool's recovery timescale is what its
exhaustion means.** Each tier has a depletion process, a recovery process, and a failure meaning,
and the three are bound together by the tier's timescale. *Fast* pools (the readily-releasable
vesicle pool) deplete and recover fast, so their shortfall is transient — short-term depression,
self-correcting within a second once activity slows. *Medium* pools (the operational budget)
deplete and recover at the medium scale, so their shortfall is a standing constraint, not
instantly self-correcting — which is exactly why it is worth recording as endurance evidence.
*Persistent* capacity (structure) changes only at NIGHT, so its "shortfall" is a structural limit
that cannot be fixed in DAY at all. The recovery timescale of a pool therefore determines what
kind of thing its exhaustion *is*: a passing inconvenience, a standing problem worth consolidating
against, or a hard ceiling. This is the same "timescale = meaning" principle that governs traces,
now applied to pools — and it is why the model can read a behavior's failure mode off which pool
ran dry: fast-pool exhaustion is STD, medium-pool exhaustion is endurance evidence, persistent-pool
limit is structural. Depletion and recovery are the pool-side mirror of creation and decay: a pool
is drawn down by behaving and refilled toward its ceiling, just as a trace is deposited by behaving
and relaxes toward zero, and in both cases the timescale is the meaning.

---

## V. Locality

**Only local evaluation.** Every decision a component makes — to act, to deposit a trace,
to register an interrupted success — uses only information physically present in that
component. A component cannot read another compartment's internal state. The presynapse
does not know the postsynapse's calcium; the dendrite does not know which distal spines are
active; the astrosynapse does not know whether the postsynapse is waiting. Each judges from
its own state alone.

**Cross-compartment influence travels only as signals that arrive and become local.**
Information crosses a boundary only by being sent — feedforward transmission, retrograde
messengers, neuromodulatory broadcast. A signal in transit is invisible; a signal that has
arrived is local and can be read. The presynapse can incorporate downstream success only
through the portion the postsynapse chose to release as a retrograde messenger, and only
after it landed. Downstream reaches upstream by emitting; upstream never reaches into
downstream.

**Each component's notion of success is its own.** Because evaluation is local, "was my
interrupted behavior worth sustaining" is answered by the component's own activity —
was I working hard and effectively from my own point of view — optionally amplified by
feedback that has arrived. The local proxy differs by component (strong release for the
presynapse, climbing calcium for the postsynapse, strong propagation for the axon) but the
shape is identical everywhere: my own vigorous, effective activity, plus whatever feedback
reached me.

---

## VI. Validation and Non-Locality

**Short-term change is local; long-term change is non-local.** A component can transiently
strengthen from its own activity alone — occupancy rises with calcium, no permission needed.
But permanent change requires validation from beyond itself. Cheap reversible change is
autonomous; expensive permanent change requires external authorization.

**Permanent change requires coincidence across spatial scales.** A tag forms only when a
local eligibility signal meets one or more non-local confirmations that have arrived as
signals. The number of required coincidences reflects the component's position in the
hierarchy — the postsynapse, the primary memory locus, requires three (astrosynapse,
soma, organism). Each scale confirms something the previous scale cannot know about itself.

**The whole validates the part; the part cannot validate itself.** A synapse cannot know
whether its activity was behaviorally significant — that information exists only at the
organism level and arrives as the neuromodulatory broadcast. This is why the system is
open: the highest validation enters from outside any component being modified, carried
inward as a signal that becomes local at the point of use.

**Strength is associative; endurance is homeostatic.** Strength requires significance —
the dopamine coincidence that says "this was worth saving." Endurance requires only that
fuel, not structure or significance, was the binding constraint on a forming success — it
needs no validation, because metabolic sustainability is not the organism's to judge. A
component earns strength by completing validated coincidences and earns endurance by
running out of fuel at the verge of its own local success.

---

## VII. Selection and Asymmetry

**Potentiation is the active drive; depotentiation is its shadow.** The entire machinery
is oriented toward strengthening what is significant and sustaining what is fuel-limited.
There is no symmetric machinery for weakening. Weakening happens to whatever the building
machinery did not select, as a consequence of the resources building consumed. The system
is built to learn; forgetting is the cost of learning.

**Depression is never explicit — it is what happens when building does not.** No signal
says "weaken this." Ceilings of both kinds decay continuously and are held up only by
maintenance. When building consumes the shared resources, unmaintained ceilings drift down.
Depression is the absence of maintenance, not the presence of a depression signal — and the
same is true of lost endurance, which is idle metabolic capacity removed for lack of use.

**Selection requires winning on multiple independent criteria.** To be permanently
strengthened a synapse must be both active enough to be fueled and significant enough to be
validated — independent gates. To be sustainable it must additionally earn endurance where
fuel was the limit. Activity without significance is not saved; significance without
sustainable activity cannot be maintained. The conjunction filters for connections that are
genuinely valuable and genuinely viable.

**Equilibrium is the residual of imperfection.** Where alignment or balance is achieved,
the very success removes the signal that drove it, allowing slow drift back toward
imbalance, which regenerates the driving signal. The soma that aligns to its input rhythm
stops generating the mismatch that aligned it, drifts, and re-aligns. The component that
builds enough endurance stops depleting, loses the endurance signal, and lets capacity
decay until depletion returns. The system hovers near optimum, never resting there,
continuously corrected by the small errors its own imperfect state produces.

---

## VIII. Bottom-Up Emergence

**Complex temporal behavior emerges from local reactive traces, not explicit computation.**
The soma aligns with its input rhythm without representing the rhythm — it leaves a trace
when input arrives during refractoriness and lets that trace speed future recovery.
Prediction, anticipation, and rhythm-tracking emerge from purely local reactive deposits,
never from a model of the future.

**The system never represents what it is becoming tuned to.** A potentiated synapse does
not contain a representation of its pattern — it is physically biased toward it. The tuning
is the structure, not a description of the structure. Prediction is implicit physical bias,
not explicit expectation. The same is true of every adaptation: refractory alignment,
endurance conditioning, astrosynaptic wrapping — all are bias, none is description.

**Global organization arises from local competition.** Sparsification, normalization, and
winner-take-more dynamics are nowhere computed centrally. They emerge automatically from
many local units drawing from shared pools. The astrocyte does not decide which synapses to
fuel — the synapses' own demands, each a purely local quantity, competing for capped
production, produce the allocation. No allocator exists; the allocation is real.

---

## IX. Coupling, Openness, and Boundedness

**Couplings create trajectories, not just states.** Some variables, once moved, make
further movement in the same direction easier — the astrosynapse wrapping tighter after
potentiation, which makes future potentiation easier. These self-reinforcing couplings give
the system momentum: it does not merely occupy states, it follows trajectories, deepening
whatever direction it has begun. The astrosynapse is the strongest such coupling — the gain
control that reshapes the input itself, amplifying whatever trajectory the synapse is on.

**The same signal can serve opposite functions through different receptors.** Glutamate
spillover brakes the presynapse while exciting the astrocyte — one ligand, two receptor
types, opposite cascades, simultaneous opposite effects. Function is determined by the
receiver, not the signal. One event coordinates multiple responses with no coordinating
mechanism.

**Energy availability is itself a selective pressure, parallel to validation.** Beyond the
explicit activity-and-reward gating, the simple availability of fuel continuously selects
which components can participate. A synapse that cannot be fueled cannot generate the
activity that would let it be tagged. Metabolism silently shapes what can be learned, in
parallel with and independent of the plasticity machinery.

**The system is finite and open, not infinite and closed.** It has bounded components and a
bounded state space, and it receives inputs it cannot generate from within — sensory drive,
neuromodulatory validation, metabolic supply. Because it is finite, its self-modification
does not generate infinite regress. Because it is open, its highest validation comes from
outside itself.

**The fixed points are made explicit, not hidden.** The parameters the system cannot modify
from within — thresholds, the vascular ceiling, the neuromodulatory signals — are declared
as fixed. They are the system's boundary with what it did not set and cannot inspect.
Making them explicit is the honest acknowledgment that every self-modifying system operates
within constraints it did not choose.

**Validation comes from embedding, not from internal consistency.** The system does not
certify its own changes. Whether a structural change was good is answered by the organism's
subsequent experience in the world, fed back through the neuromodulatory system. Correctness
is determined by the coupling between system and environment, not by any internal criterion.
The fixed point lies outside: the system acts, the world responds, and the response — not
any internal check — determines what was worth keeping.

---

## X. From Local Expression to Holistic System

The preceding principles are stated almost entirely in local terms. Every behavior is a
local component acting on its own state within its own budget. Every evaluation uses only
local information and signals that have arrived. Every trace is a local record; every tag a
local conjunction; every commit a local draw on a shared pool. Nowhere is there a central
controller, a global plan, a representation of the whole. And yet the system behaves as a
whole. This final category states why the local necessarily becomes holistic.

**The whole exists in the shared pools, not in any component.** The only thing every
component touches is the finite resource it competes for. No component sees the whole, but
every component is coupled to every other through the pool they share. When one draws, all
others have less; when one returns, all others have more. The pool is the medium through
which purely local actions become globally consequential. The holism is not represented
anywhere — it is enacted in the competition for a common, capped resource.

**Coincidence across scales stitches the levels into one.** A permanent change at the
smallest scale requires confirmation from progressively larger scales — astrosynapse, soma,
organism. Each scale contributes what the scale below cannot know about itself. The result
is that no permanent change reflects a single level; every one reflects an agreement across
all levels that happened to align in a window. The system's memory is therefore never local
even though every step that produced it was. The whole writes itself into the part, through
the part's requirement for non-local confirmation.

**Signals make the boundaries permeable without dissolving them.** Components remain
strictly local — they cannot read each other — yet they are not isolated, because they emit
and receive signals. Feedforward transmission, retrograde feedback, and broadcast
neuromodulation knit the local components into a communicating whole without ever giving any
component access to another's interior. The system is simultaneously fully local in its
evaluation and fully connected in its dynamics. This is the precise sense in which a
holistic system is built from local parts: not by any part containing the whole, but by the
parts being coupled through resources and signals into a dynamics that no part could produce
alone.

**The whole has properties no component has.** Sparsification, rhythm, equilibrium,
prediction, memory, the joint selection for significance-and-sustainability — none of these
exists in any single component. They are properties of the coupled population drawing on
shared pools and exchanging signals over the DAY-NIGHT cycle. The component knows only its
own state and its own budget; the system knows what to remember, what to sustain, and what
to let fade. The gap between these is not bridged by any component understanding more — it
is bridged by the structure of the coupling itself. The holistic behavior is real, it is
not represented anywhere, and it could not be removed without removing the couplings that
constitute it.

**This is what it means for understanding to be enacted rather than encoded.** The system
does not contain a model of what it is doing. It does not represent the pattern it learns,
the rhythm it tracks, or the criterion by which it selects. Each of these is a physical bias
distributed across local components coupled through shared resources and signals. The whole
is not in any part and not in any representation — it is in the doing, in the ongoing
competitive, signal-mediated, scope-alternating process itself. A local expression, faithful
to locality at every step, produces a holistic system precisely because the locality is
coupled — and coupling, not representation, is what makes a whole.
