Version: 1.0
Date: 2025-12-15
Status: Working document


Overview

This document compares the different layer models that have emerged across SIL documentation. The goal is to understand the differences, evaluate trade-offs, and converge on a canonical model.


Model Summary Table

Layer Canonical (Glossary) Original Semantic OS Feedback Loops Observability Provenance-First
L7 - - - Applications -
L6 Intelligence - Applications Agent Orchestration Reflection
L5 Intent Human Interfaces Agent Orchestration Pantheon Execution
L4.5 - - - Observability -
L4 Dynamics Deterministic Engines Semantic Primitives TIA Composition
L3 Composition Agent Ether Feedback & Reflection Beth Intent
L2 Structures Domain Modules Tool Infrastructure Domain modules Trust
L1 Primitives Pantheon IR Storage & Indexing Semantic primitives Meaning
L0 Substrate Semantic Memory - - Provenance
L-1 Arena (implicit) - - - -
Meta Observability - - - -

Model 1: Canonical (Glossary v2.2)

Source: SIL_GLOSSARY.md
Status: Current canonical reference

L6: Intelligence    - Agents, Planning, Adaptation (Agent Ether, BrowserBridge)
L5: Intent          - Goals, Constraints, Roles (Pantheon validation)
L4: Dynamics        - Time, Behavior, Execution (Morphogen scheduler)
L3: Composition     - Graphs, Routing, Topology (Pantheon IR, SUP)
L2: Structures      - Semantic Units, Types (TiaCAD, GenesisGraph)
L1: Primitives      - Irreducible Operations (Morphogen domains, RiffStack)
L0: Substrate       - Physical/Computational Reality (Philbrick hardware)
─────────────────────────────────────────────────────────────────────────
Meta: Observability - Cross-cutting (Reveal)

Characteristics:
- Hardware-grounded (Philbrick at L0)
- Observability as meta-layer
- Product-centric assignment
- 7 layers + meta

Patron Saints (from OSI_LAYER_MAPPING):
- L6: Marvin Minsky (Agents)
- L5: Douglas Engelbart (Augmentation)
- L4: Alan Turing (Computation)
- L3: Claude Shannon (Information)
- L2: George Philbrick (Modularity)
- L1: Harold Black (Feedback)
- L0: Richard Feynman (Physics)


Model 2: Original Semantic OS (6-Layer)

Source: SIL_SEMANTIC_OS_ARCHITECTURE.md (pre-alignment)
Status: Historical, partially updated

L5: Human Interfaces
L4: Deterministic Engines (Morphogen)
L3: Agent Ether
L2: Domain Modules
L1: Pantheon IR
L0: Semantic Memory

Characteristics:
- Memory-grounded (Semantic Memory at L0)
- Human interfaces at top
- Agent Ether as middleware (L3)
- 6 layers, no meta


Model 3: Feedback Loops (6-Layer)

Source: SEMANTIC_FEEDBACK_LOOPS.md
Status: Historical

L6: Applications (Scout, Morphogen)
L5: Agent Orchestration (agent-ether)
L4: Semantic Primitives (USIR, knowledge graphs)
L3: Feedback & Reflection
L2: Tool Infrastructure (reveal, tia)
L1: Storage & Indexing (Beth, Gemma)

Characteristics:
- No L0 defined
- Feedback as explicit layer (L3)
- Tool infrastructure prominent
- Application-focused top layers


Model 4: Observability (7-Layer + L4.5)

Source: SEMANTIC_OBSERVABILITY.md (pre-alignment)
Status: Historical, had unique L4.5

L7: Applications (Scout, Reveal, Agent-Ether)
L6: Agent Orchestration
L5: Pantheon
L4.5: SEMANTIC OBSERVABILITY  ← Unique!
L4: TIA
L3: Beth
L2: Domain modules
L1: Semantic primitives

Characteristics:
- Observability as full layer (L4.5)
- Tools as layers (TIA at L4, Beth at L3)
- 8 effective layers
- Most tool-centric model


Model 5: Provenance-First (Proposed)

Source: sessions/heating-snow-1214/README_2025-12-15_08-52.md
Status: Proposed alternative

L6: Reflection      - Learning from execution (observability)
L5: Execution       - Doing work under constraints (agents)
L4: Composition     - Cross-domain integration (Pantheon IR)
L3: Intent          - What we're accomplishing (contracts)
L2: Trust           - Who can do what (TAP, Authorization)
L1: Meaning         - Embeddings, types, similarity (Beth, Pantheon)
L0: Provenance      - Everything has lineage (GenesisGraph)

Characteristics:
- Problem-centric (solves LLM coexistence)
- Provenance as foundation
- Trust as explicit layer
- Philbrick becomes optional backend
- Tools span layers (like Unix utilities)

Design Rationale:
If core problems are:
1. Decomposing intent into trackable work
2. Trust relationships for LLM/AGI coexistence
3. Cross-domain tooling
4. Meaning manifolds for analogies

Then layers should reflect those problems, not products.

Unix Philosophy Parallel:
- Unix insight: "Everything is a file"
- Semantic OS insight: "Everything has meaning and provenance"


Component Assignment Comparison

Component Canonical Original Feedback Observability Provenance-First
Agent Ether L6 L3 L5 L6/L7 L5 (Execution)
Morphogen L1+L4 L4 L6 - spans L4-L5
Pantheon IR L3 L1 L4 L5 L4 (Composition)
GenesisGraph L2 - - - L0 (Foundation)
Beth L2 - L1 L3 L1 (Meaning)
Reveal Meta - L2 L7 spans layers
TIA - - L2 L4 spans L3-L6
SUP L3 - - - L4 (Composition)
Philbrick L0 - - - backend (optional)
Human Interfaces L5 L5 - - L6 (Reflection)

Key Architectural Questions

1. What is L0?

Model L0 Definition Implication
Canonical Substrate (hardware) Architecture is hardware-up
Original Semantic Memory Architecture is memory-up
Provenance-First Provenance (lineage) Architecture is trust-up

Question: Is the foundation hardware, memory, or trust?

2. Where do tools fit?

Approach Examples Implication
Tools as layers TIA at L4, Beth at L3 Tools are architectural components
Tools span layers TIA spans L3-L6 Tools are utilities, not layers
Tools as meta Reveal as meta-layer Tools observe, don't participate

Question: Should TIA/Beth/Reveal be layers or cross-cutting utilities?

3. Is Observability a layer or meta?

Model Observability Location Implication
Canonical Meta-layer Orthogonal concern
Observability L4.5 First-class layer
Provenance-First L6 (Reflection) Part of learning loop

4. Where does Trust/Authorization fit?

Model Trust Location Implication
Canonical L5 (Intent) Trust is part of goal-setting
Provenance-First L2 Trust is structural foundation

Cross-Cutting Concerns (All Models)

Regardless of layer assignment, these span the stack:

  1. Provenance - Who made what, when, from what
  2. Trust - Who can do what to whom
  3. Observability - What's happening, how well
  4. Feedback - Learning from execution

The Provenance-First model makes two of these (Provenance, Trust) explicit layers rather than cross-cutting.


Critical Missing Subsystems

The coral-shine-1212 and brewing-sleet-1212 sessions identified three subsystems that don't yet exist but are critical for any model:

1. Intent Verification Subsystem

Problem: No mechanical way to verify that an action preserves the original intent.

Solution: Intent as cryptographic primitive - asymmetric verification where it's easy to check but hard to fake.

Model Where It Lives
Canonical L5 (Intent)
Original L5 (Human Interfaces)
Feedback L3 (Feedback & Reflection)
Observability L6 (Agent Orchestration)
Provenance-First L3 (Intent) - explicit intent layer

Components needed:
- intent.py - Intent object schema
- signature.py - Intent signature verification
- contract.py - Contract enforcement
- amendment.py - Intent versioning

2. Uncertainty Tracking Subsystem

Problem: Uncertainty compounds geometrically through operations; system can't detect or prevent runaway uncertainty.

Solution: Uncertainty as first-class field - track assumptions, coupling, and propagation gradients.

Model Where It Lives
Canonical Meta (Observability)
Original (implicit)
Feedback L3 (Feedback & Reflection)
Observability L4.5
Provenance-First L6 (Reflection) - learning from execution

Components needed:
- uncertainty.py - UncertaintyProfile schema
- propagation.py - Gradient tracking
- brakes.py - Abort semantics, checkpoints

3. Cross-Domain Translation Subsystem

Problem: Domains translate meaning ad-hoc; invariants not preserved; loss untracked.

Solution: Semantic operators with contracts - like FFT preserving information while changing representation.

Model Where It Lives
Canonical L3 (Composition)
Original L1 (Pantheon IR)
Feedback L4 (Semantic Primitives)
Observability L5 (Pantheon)
Provenance-First L4 (Composition) - cross-domain integration

Components needed:
- operator.py - SemanticOperator base class
- invariant.py - Invariant schema
- registry.py - Operator catalog
- verification.py - Round-trip testing

Subsystem Layer Mapping Summary

Subsystem Provenance-First Layer Math Analogy
Intent Verification L3 (Intent) Cryptography (asymmetric verification)
Uncertainty Tracking L6 (Reflection) Thermodynamics (entropy flow)
Cross-Domain Translation L4 (Composition) FFT (invariant preservation)

Key Insight: These aren't new ideas - we're applying proven mathematical patterns to semantic computing.


Evaluation Criteria

To decide on a canonical model, evaluate against:

  1. Problem fit - Does it help with LLM coexistence, cross-domain work?
  2. Conceptual clarity - Can you explain it in 2 minutes?
  3. Component coherence - Do assignments make sense?
  4. Extension path - Can new projects find their place?
  5. Implementation guidance - Does it help developers?

See MODEL_EVALUATION.md for detailed analysis.


Session References


Next Steps

  1. [ ] Complete MODEL_EVALUATION.md with criteria scoring
  2. [ ] Draft PROVENANCE_FIRST.md with full rationale
  3. [ ] Get stakeholder input on key questions
  4. [ ] Propose canonical model
  5. [ ] Update source documents to align