SilverSight/docs/GLOSSARY.md

# SilverSight Glossary

A living dictionary of terms used across the SilverSight core, libraries,
documentation, and receipts.  When you introduce a new domain term, add it here
and cite the module that owns the definition.

**Rule:** every entry must name the authoritative source file or module.  A
glossary entry without a source module is a draft; it must be promoted to a
bound definition before it is used in a receipt or gate.

---

## Standard terminology crosswalk

SilverSight invents names only when necessary.  When a concept already exists
under a standard name, the glossary binds the SilverSight name to the standard
name and explains the delta.

| SilverSight term | Standard terminology | Delta / note |
|------------------|----------------------|--------------|
| **Sidon set** | B₂ sequence, Erdős–Sidon set | Standard combinatorial object; SilverSight uses it for deterministic strand addressing. |
| **Sidon label** | Sidon-set element, B₂ address | Chosen from the canonical powers-of-2 set for 8-strand braids. |
| **Q16_16** | Fixed-point arithmetic, Q15.16 / s16.16 | Signed 32-bit fixed point with 16 integer and 16 fractional bits. |
| **BraidStorm** | Braid group representation, Artin braid | 8-strand braid action used as a compression/determinism substrate. |
| **eigensolid** | Fixed point, attractor | Fixed point of the `crossStep` operator; not a physical solid. |
| **crossStep** | Braid generator / crossing operator | One deterministic update step in the braid dynamics. |
| **AVM** | Abstract/virtual machine, stack machine | SilverSight-specific instruction set and transition relation. |
| **TIC** | Logical clock, event counter | Monotone counter derived from AVM transitions. |
| **Receipt** | Attestation, certificate, proof certificate | Machine-readable record of a gate result; the compressed state. |
| **Hachimoji** | 8-letter alphabet, octal state | The 8-symbol output alphabet of the core classifier. |
| **Finsler-Randers** | Asymmetric metric, quasimetric | Directed routing cost with anisotropy parameter β. |
| **QUBO** | Ising model, binary quadratic optimization | Energy minimization over binary variables. |
| **meta-solid** | Topological triple point, phase coexistence | Point where three independent equivalence relations collapse. |
| **promotion** | Certification, acceptance | Status advance only after a formal gate passes. |
| **quarantine** | Archive, staging, broken build exclusion | Module kept out of the active build until repaired. |
| **Genome18** | Codon LUT, k=6 fixed-point address | Research Stack vocabulary-lock name for `CodonLUT (k=6)`: 6 × 3-bit Hachimoji inputs → 18-bit address. SilverSight binds this to `formal/CoreFormalism/HachimojiLUT.lean CodonLUT`. |
| **equationPosition** | Manifold localization, equation embedding | The deterministic map `EquationShape → SpherePoint` that answers "where does this equation live on the manifold?" |

---

## Core terms

| Term | Definition | Source module |
|------|------------|---------------|
| **Hachimoji state** | One of the 8 output symbols `Φ Λ Ρ Κ Ω Σ Π Ζ` produced by the core classifier. | `Core/SilverSightCore.lean` |
| **Receipt** | The compressed, machine-readable attestation record that crosses the Core/library boundary. It is not metadata around a result; it *is* the result. | `Core/SilverSightCore.lean` |
| **AVM** | Adaptive Virtual Machine. The stack-machine transition semantics `δ` defined in the core; the universal bridge between math languages and executable traces. | `Core/SilverSightCore.lean` |
| **TIC** | Temporal Index of Computation. A monotone event counter derived from AVM state transitions. | `Core/SilverSightCore.lean` |
| **pathCost** | Raw integer cost metric carried on a `Receipt`; never a `Float`. | `Core/SilverSightCore.lean` |
| **Library method** | The architecture rule: `Core/` defines contracts, libraries implement them, and no library imports another library. | `AGENTS.md` |
| **Core** | The invariant center of SilverSight: `Core/SilverSightCore.lean` and `Core/SilverSight/FixedPoint.lean`. Defines Receipt, AVM, TIC, and canonical Q16_16. | `AGENTS.md` |
| **Schema** | Typeclass describing fixed-size, well-formed data: `byteSize` and `wellFormed`. | `Core/SilverSight/Semantics/Schema.lean` |
| **byteSize** | Number of bytes occupied by a value of a `Schema` type; constant and statically known. | `Core/SilverSight/Semantics/Schema.lean` |
| **wellFormed** | Predicate asserting that a value satisfies its `Schema` invariants. | `Core/SilverSight/Semantics/Schema.lean` |
| **Layout** | Physical data placement: `rowMajor`, `columnar`, `compact`, `mmapView`. | `Core/SilverSight/Semantics/Layout.lean` |
| **AccessProfile** | Read/write mix used by the layout cost model. | `Core/SilverSight/Semantics/Layout.lean` |
| **WireFormat** | Certified encoder/decoder pair for a `Schema` under a `Layout`. | `Core/SilverSight/Semantics/WireFormat.lean` |
| **roundTrip** | WireFormat axiom: `decode (encode a) = some a` for every value. | `Core/SilverSight/Semantics/WireFormat.lean` |
| **View** | Zero-copy, address-bounded window into a `ByteArray`. | `Core/SilverSight/Semantics/View.lean` |
| **LayoutBridge** | Certified conversion between two `Layout`s with a round-trip guarantee. | `Core/SilverSight/Semantics/LayoutBridge.lean` |
| **CanalRegime** | Storage regime (`cold`, `warm`, `hot`, `flash`) used by layout selection. | `Core/SilverSight/Semantics/CanalLayout.lean` |
| **CanalLayout** | Module that maps `CanalRegime` to a preferred `Layout` and profile. | `Core/SilverSight/Semantics/CanalLayout.lean` |
| **rowMajor** | Default `Layout`: fields stored contiguously in declaration order. | `Core/SilverSight/Semantics/Layout.lean` |
| **mmapView** | `Layout` optimized for memory-mapped, read-only access. | `Core/SilverSight/Semantics/Layout.lean` |
| **BraidState** | Aggregated braid carrier state used by the eigensolid compressor. | `formal/CoreFormalism/BraidState.lean` |

## RRC / AVM ISA

| Term | Definition | Source module |
|------|------------|---------------|
| **RRC** | Receipt Routing Classifier. Aligns PIST structural labels with RRC semantic routing shapes and emits gate receipts. | `formal/SilverSight/RRC/Emit.lean` |
| **CoreFormalism** | The SilverSight foundational library containing canonical Q16_16, Sidon sets, braid dynamics, and related lemmas. | `formal/CoreFormalism/` |
| **RRCShape** | One of six lawful routing shapes: `cognitiveLoadField`, `signalShapedRouteCompiler`, `logogramProjection`, `projectableGeometryTopology`, `cadForceProbeReceipt`, `holdForUnlawfulOrUnderspecifiedShape`. | `formal/SilverSight/RRCLogogramProjection.lean` |
| **WitnessStatus** | `candidate` (admits next-stage checks) or `hold` (blocked pending more evidence). | `formal/SilverSight/RRCLogogramProjection.lean` |
| **LogogramReceipt** | Receipt core for one compiled logogram projection, carrying shape, status, regime, and tear evidence. | `formal/SilverSight/RRCLogogramProjection.lean` |
| **FixtureRow** | One compiled equation record with raw features and optional PIST labels; input to the RRC alignment gate. | `formal/SilverSight/RRC/Emit.lean` |
| **AlignmentStatus** | Result of `determineAlignment`: `alignedExact`, `alignedProxy`, `compatibleStructuralProjection`, `alignmentWarning`, or `missingPrediction`. | `formal/SilverSight/RRC/Emit.lean` |
| **determineAlignment** | RRC alignment gate that maps a `FixtureRow` and optional PIST labels to an `AlignmentStatus`. | `formal/SilverSight/RRC/Emit.lean` |
| **AvmTy** | Closed-world AVM type universe: `q0_16`, `q16_16`, `bool`. | `formal/SilverSight/AVMIsa/Types.lean` |
| **AvmVal** | Typed AVM value payload indexed by `AvmTy`. | `formal/SilverSight/AVMIsa/Value.lean` |
| **Instr** | AVM instruction set: `push`, `pop`, `dup`, `swap`, `load`, `store`, `jump`, `jumpIf`, `prim`, `halt`. | `formal/SilverSight/AVMIsa/Instr.lean` |
| **Prim** | Finite AVM primitive set: boolean ops and saturating Q0_16/Q16_16 add/sub. | `formal/SilverSight/AVMIsa/Instr.lean` |
| **AVMIsa.Emit** | Top-level JSON output boundary. Stamps AVM canary receipts and RRC corpus bundles. | `formal/SilverSight/AVMIsa/Emit.lean` |

## Fixed-point and numerics

| Term | Definition | Source module |
|------|------------|---------------|
| **Q16_16** | Canonical 32-bit fixed-point type: 16 integer bits and 16 fractional bits. The sole source of truth for core arithmetic. | `Core/SilverSight/FixedPoint.lean` |
| **Q0_16** | 16.16-style fixed-point interpretation used for bounded unit-interval quantities. | `Core/SilverSight/FixedPoint.lean` |
| **ofFloat** | Conversion from `Float` to `Q16_16`. Permitted **only** at external boundaries (JSON parsing, sensor input); must be immediately bracketed. | `AGENTS.md` |
| **ofNat / ofRatio / ofRawInt** | Canonical constructors for `Q16_16` values in compute paths. | `Core/SilverSight/FixedPoint.lean` |
| **Float** | IEEE-754 floating-point type. Forbidden in SilverSight compute paths; permitted only at external JSON/sensor boundaries and must be immediately converted to `Q16_16`. | `AGENTS.md` |

## Braid / eigensolid compression

| Term | Definition | Source module |
|------|------------|---------------|
| **BraidStorm** | The 8-strand braid topology used by the eigensolid compressor. Strands cross pairwise; each crossing merges phase and produces a residual. | `formal/CoreFormalism/BraidEigensolid.lean` |
| **eigensolid** | The converged, stable state of a braid crossing loop; detected when `crossStep(s) = s`. | `formal/CoreFormalism/BraidEigensolid.lean` |
| **crossStep** | One braid-crossing iteration that merges phase and emits a residual. | `formal/CoreFormalism/BraidCross.lean` |
| **strand** | A single braided carrier with phase accumulator, parity, slot, residue, jitter, and admissibility bracket. | `formal/CoreFormalism/BraidStrand.lean` |
| **Yang-Baxter** | The braid relation `βij βjk βij = βjk βij βjk` that defines braid-order invariance. | `formal/CoreFormalism/BraidEigensolid.lean` |
| **Anti-BraidStorm** | Adversarial dual that tests Yang-Baxter invariance and receipt aliasing. | `PORTING_MAP.md` (planned) |

## Sidon / number theory

| Term | Definition | Source module |
|------|------------|---------------|
| **Sidon set** | A set where all pairwise sums `a + b` are unique up to reordering. | `formal/CoreFormalism/SidonSets.lean` |
| **Sidon label** | An address from a Sidon set. Powers of 2 `{1,2,4,8,16,32,64,128}` are canonical for 8 strands. | `formal/CoreFormalism/InteractionGraphSidon.lean` |
| **Sidon slack** | Address budget minus the maximum label used; encodes capacity headroom. | `formal/CoreFormalism/SidonSets.lean` |
| **IsIntervalSidon** | Predicate stating that a finite set is a Sidon subset of `{1,…,N}`. | `formal/CoreFormalism/SidonSets.lean` |
| **IsSidonMod** | Predicate stating that a set is Sidon modulo `M`: sums are unique up to congruence. | `formal/CoreFormalism/SidonSets.lean` |
| **sidonMaximum** | Extremal function `h(N)` returning the maximum size of an interval Sidon set. | `formal/CoreFormalism/SidonSets.lean` |
| **Singer theorem** | Existence of a Sidon set of size `q+1` modulo `q²+q+1` for prime powers `q`. | `formal/CoreFormalism/SidonSets.lean` |
| **Lindström bound** | Upper bound `|A| ≤ √N + O(N^{1/4})` for interval Sidon sets. | `formal/CoreFormalism/SidonSets.lean` |
| **interaction graph** | Typed directed graph whose adjacency matrix is tested for the Sidon witness property. | `formal/CoreFormalism/InteractionGraphSidon.lean` |
| **weak-axis CRT** | Chinese Remainder Theorem reconstruction used for RRC weak-axis classification. | `formal/CoreFormalism/SieveLemmas.lean` |

## RRC / receipt classification

| Term | Definition | Source module |
|------|------------|---------------|
| **RRC** | Receipt / Rank / Classify pipeline. The decision layer that admits or rejects prediction rows. | `PORTING_MAP.md` |
| **Corpus250** | The 250-equation raw-feature corpus used for RRC training and alignment. | Research Stack `Semantics.RRC.Corpus250` (planned) |
| **emit** | The sole output boundary for top-level receipt JSON. Only the designated emitter may stamp a receipt. | `AGENTS.md` |
| **promotion** | Status advance from `not_promoted` to `promoted` only after a Lean gate explicitly passes. | `AGENTS.md` |

## Hachimoji Manifold & LUT (added 2026-06-22)

| Term | Definition | Source module |
|------|------------|---------------|
| **PhaseCircle** | ℤ/360ℤ — 360 discrete phase positions with `AddCommGroup` structure.  Foundation of the Hachimoji encoding; the 8 canonical bases occupy the order-8 subgroup at multiples of 45°. | `formal/CoreFormalism/HachimojiLUT.lean §0` |
| **phaseEmbed** | Embedding `PhaseCircle → SpherePoint`; maps phase θ to `(cos(θ·π/180), 0, sin(θ·π/180), 0, …)` on S¹⁵.  Corrected from v.01: uses `π/180` (full period) not `π/360` (semicircle). | `formal/CoreFormalism/HachimojiLUT.lean §2` |
| **SpherePoint** | A point on S¹⁵: 16-vector `coords : Fin 16 → ℝ` satisfying `∑ coords i ^ 2 = 1`.  Represents one character position in the 16D DQ complexified quaternion space. | `formal/CoreFormalism/HachimojiLUT.lean §2` |
| **stateIndex** | `HachimojiState4D → Fin 8`; maps each canonical Hachimoji state to its index 0–7 via `phase / 45 % 8`.  Resolves the missing `Base.index` from the v.01 exploration file. | `formal/CoreFormalism/HachimojiLUT.lean §1` |
| **equationPosition** | `EquationShape → SpherePoint`; the formal bridge from equation structure to manifold position.  Pipeline: `classifyEquation → stateToPhase → phaseEmbed`. | `formal/CoreFormalism/HachimojiLUT.lean §4` |
| **VirtualLUT** | A mapping from k sphere points to one output, defined by manifold geometry rather than stored memory.  Three levels: k=2 (BinaryLUT), k=6 (CodonLUT), k=50 (GenomeLUT). | `formal/CoreFormalism/HachimojiLUT.lean §5` |
| **BinaryLUT** | `VirtualLUT 2`; composition table for pairs of Hachimoji states (8×8 = 64 entries).  Defines how two equations compose geometrically. | `formal/CoreFormalism/HachimojiLUT.lean §5` |
| **CodonLUT** | `VirtualLUT 6`; 6-character Hachimoji codon mapping to one admitted state.  Direct formal correspondent of the Research Stack `Genome18` primitive (6 × 3-bit bins → 18-bit address). | `formal/CoreFormalism/HachimojiLUT.lean §5` |
| **GenomeLUT** | `VirtualLUT 50`; universal 50-character Hachimoji string mapping to a path on (S¹⁵)⁵⁰.  Corresponds to the `UniversalMathEncoding` 50-token address space. | `formal/CoreFormalism/HachimojiLUT.lean §5` |
| **stability point** | A phase θ fixed under conjugation `θ ↦ −θ` on ℤ/360ℤ.  Proved: exactly {0°, 180°} = Φ (trivial) and Ω (collision).  These are the self-complementary (ambidextrous) bases — the "DNA palindromes" of the encoding. | `formal/CoreFormalism/HachimojiLUT.lean §6` |
| **conjugate** | `PhaseCircle → PhaseCircle`; the map `θ ↦ (360 - θ) % 360`.  The binding law dual to Watson-Crick complementarity: each base pairs with its conjugate; stability points are self-paired. | `formal/CoreFormalism/HachimojiLUT.lean §6` |
| **octagon chord** | Euclidean distance between adjacent canonical bases under `phaseEmbed`; equals `sqrt(2 - 2·cos(π/4)) = 2·sin(π/8) ≈ 0.7654`.  Proved formally (not vacuous as in v.01). | `formal/CoreFormalism/HachimojiLUT.lean §2` |
| **HachimojiTokenEmbed** | Planned module for fine-grained manifold position. Uses Fourier harmonics of the phase angle across all 16 S¹⁵ coordinates: coords (0,2) = (cos θ, sin θ), (4,6) = (cos 2θ, sin 2θ), (8,10) = (cos 4θ, sin 4θ), (12,14) = (cos 8θ, sin 8θ). Gauge-equivariant under state relabeling; norm constraint provable via `cos_sq_add_sin_sq`. See `docs/hachimoji_torsor_consequences.md` §2. | Planned: `formal/CoreFormalism/HachimojiTokenEmbed.lean` |

## Physics / applied math (ported concepts)

| Term | Definition | Source module |
|------|------------|---------------|
| **meta-solid** | Topological triple point where trace closure, local Yang-Baxter isotopy, and braid class are simultaneously exact. | ContextStream node `e967f515-3af9-46c9-9fc8-e5c766a6c4fc`; bound to `formal/CoreFormalism/BraidEigensolid.lean` |
| **Finsler-Randers** | Directed routing metric used in the QUBO/TSP benchmark. | `qubo/finsler_metric.py` (planned) |
| **QUBO** | Quadratic Unconstrained Binary Optimization; a classical/quantum optimization encoding. | `qubo/qubo_builder.py` (planned) |
| **BMCTE** | Bosonic Monte Carlo Tensor Estimation class: problems solvable by O(S·(Np+p²2^p)) stochastic contraction of Sym^p(U) without explicit Fock-space construction. | `experiments/bosonic_continuous/kernel/ryser_continuous.py` |
| **BoseMonteCarloEstimator** | Stochastic estimator P^p(U) = Σ_k |Per(U_{S_k})|² / K! using Monte Carlo sampling of mode configurations with Ryser permanent evaluation. | `4-Infrastructure/shim/rrc_bosonic_tensor_network.py` |
| **ContinuousInterpolation** | λ(p) = exp(-p²/N) smooth blending parameter between fully bosonic (λ→1) and weakly-correlated (λ→0) regimes. | `experiments/bosonic_continuous/tests/test_lambda_interpolation.py` |
| **EntropyInvarianceHypothesis** | In BMCTE regime, Shannon entropy H(p) ≈ 10 bits remains constant across p=1..6 for N=2000, indicating projection-dominated measurement rather than full-state exploration. | `experiments/bosonic_continuous/README.md` |

## Symbolic Regression (added 2026-06-22)

| Term | Definition | Source module |
|------|------------|---------------|
| **ExprNode** | Expression tree node: leaf (variable 'x' or constant) or internal (unary/binary operator). Supports evaluate, to_string, complexity, copy. | `python/expr_tree.py` |
| **Linear Scaling** | Keijzer 2003 technique: GP searches for shape g(x), closed-form solves f(x) = a·g(x) + b via least squares. Reduces search space dramatically. | `python/linear_scaling.py` |
| **BIC Fitness** | Bayesian Information Criterion: `n·ln(MSE) + k·ln(n)` where k = weighted complexity (var=1, const=3). Penalizes overfitting. | `python/expr_tree.py` |
| **Chaos Game Search** | IFS contraction over expression space: at each step, try to improve best expression by applying transformations. Deterministic (same input → same output). | `python/expr_tree.py` |
| **Hachimoji-Guided Search** | Use classifyEquation to partition expressions into 8 Hachimoji states (Φ=trivial, Σ=symmetric, Λ=quantified, Π=complex, Ω=contradiction). Force diversity across states. | `python/hachimoji_citation.py` |
| **Log Prescreen** | Before expression tree search, try log-log, log-y, y-x transforms. If R² > 0.999, return as discovered law. Collapses O(tree search) to O(linear regression) for power laws, exponentials, polynomials. | `python/log_prescreen.py` |
| **Finite-Infinity Duality** | SilverSight's core principle: tame infinity with finite structure. Logarithms compress combinatorial explosion; Hachimoji encoding bounds Gödel's undecidable. Both are lossy compressions that preserve enough structure to discover physical laws. | `docs/FINITE_INFINITY_DUALITY.md` |
| **Gödel Boundary** | The 8-state Hachimoji encoding is a finite boundary on infinite undecidable equation space. If extended to self-referential equations (Gödel sentences), it would need to classify "this equation is not classifiable" — a NaN event. The admission gate (ADMIT/QUARANTINE/HOLD) controls this boundary. | `formal/CoreFormalism/HachimojiCodec.lean` |

## Modules and library layers

| Term | Definition | Source module |
|------|------------|---------------|
| **FixedPoint** | The Lean module that defines the canonical `Q16_16`/`Q0_16` fixed-point implementation. | `Core/SilverSight/FixedPoint.lean` |
| **SieveLemmas** | Lean module for coprime-sieve observers and CRT reconstruction. | `formal/CoreFormalism/SieveLemmas.lean` |
| **InteractionGraphSidon** | Lean module for typed interaction graphs and Sidon witnesses. | `formal/CoreFormalism/InteractionGraphSidon.lean` |
| **BraidEigensolid** | Lean module for the braid crossing loop and eigensolid fixed-point theorems. | `formal/CoreFormalism/BraidEigensolid.lean` |
| **BraidSpherionBridge** | Lean module bridging braid dynamics to spherion / twin-prime constructions. | `formal/CoreFormalism/BraidSpherionBridge.lean` |
| **SilverSightRRC** | Lean library containing the RRC decision surface, receipt bridge, and AVM ISA emit boundary. | `lakefile.lean` |
| **RRCLib** | User-facing symlink directory for the Receipt / Rank / Classify surface. | `formal/RRCLib/` |
| **RrcEmitFixture** | Lean executable that emits the AVM-stamped RRC fixture corpus JSON. | `exe/RrcEmitFixture.lean` |
| **emitFixtureCorpus** | Top-level JSON bundle for the 6-row RRC fixture corpus. | `formal/SilverSight/AVMIsa/Emit.lean` |
| **toSilverSightReceipt** | Bridge from `SilverSight.ReceiptCore.Receipt` to `SilverSight.Core.Receipt`. | `formal/SilverSight/ReceiptCore.lean` |
| **SearchLib** | Planned library layer for search-space exploration (chaos game, entropy candidates). | `PORTING_MAP.md` |
| **LexLib** | Planned library layer for lexical / symbolic encodings. | `PORTING_MAP.md` |
| **StructureLib** | Planned library layer for structural / manifold encodings. | `PORTING_MAP.md` |
| **QUBOLib** | Planned library layer for QUBO/QAOA optimization bridges. | `PORTING_MAP.md` |
| **PVGSLib** | Planned library layer for photon-varied Gaussian state bridges. | `PORTING_MAP.md` |

## Concept Map & Academic Citations

| Term | Definition | Source module |
|------|------------|---------------|
| **Concept Map** | JSONL artifact mapping files to extracted concepts with types, tags, dependencies, and summaries. 822 local + 752 Drive files. | `docs/concept_map/` |
| **Cornfield Concepts** | 48 formally grounded concepts with academic citations, novelty classification, and novelty_statements. | `extraction/cornfield_concepts.json` |
| **concept_citations** | Postgres table linking concepts to papers via paper_id, doi, title, authors, year, journal, relation_type. Now includes 480 hybrid citations from pgvector RRF matching. | neon-64gb `arxiv` DB |
| **paper_refs** | JSONB column storing structured citation array on math_objects. | neon-64gb `arxiv` DB |
| **is_novel_claim** | Boolean flag: true = original work, no prior paper covers exactly this. Requires novelty_statement. | neon-64gb `arxiv` DB |
| **relation_type** | Citation edge: `grounds` (foundational), `extends` (builds on), `applies` (application), `cites` (general), `hybrid` (RRF-trigram+vector). | neon-64gb `arxiv` DB |
| **Jaccard Matcher** | Deprecated script finding arxiv papers via keyword overlap. Replaced by hybrid_search. | `python/hachimoji_citation.py` (historical) |
| **Hybrid Matcher** | Equation-to-citation pipeline using pgvector HNSW + pg_trgm RRF (22ms query, 397x faster than transformer models). Mirrors `HachimojiCodec.lean` classifyEquation. | `python/hachimoji_citation.py` |
| **hachimoji_citation** | Equation → Hachimoji state → arXiv paper bridge. Computes structural features, classifies to one of 8 states, builds semantic query, retrieves top-k papers. Mirrors `formal/CoreFormalism/HachimojiCodec.lean`. | `python/hachimoji_citation.py` |
| **static-retrieval-mrl-en-v1** | Sentence-transformers embedding model (1024-dim), 397x faster than transformer models for arXiv abstract embedding. | arXiv embedding pipeline |
| **hnsw_index** | pgvector HNSW index (m=8, ef=100) enabling 22ms vector similarity search over 700k arxiv papers. | `idx_arxiv_embedding_hnsw` in arxiv-pg |
| **RRF** | Reciprocal Rank Fusion: merges trigram and vector search ranks without score normalization. Formula: `score = 1/(k+r1) + 1/(k+r2)` | `hybrid_search.sql` |

## PIST Trace Classifier

| Term | Definition | Source module |
|------|------------|---------------|
| **PistClassifyTrace** | Lean executable reading trace JSON, computing spectral features with Q16_16, applying RRC shape thresholds, inferring tactic family. | `PistClassifyTrace.lean` |
| **Spectral Profile** | 10-feature Q16_16 vector from transition matrix: matrix_size, rank, spectral_gap, density, trace, frobenius, laplacian_zero_count, eigenvalue_max, etc. | `PistClassifyTrace.lean` |
| **Tactic Family** | Classification: rewrite, normalization, arithmetic, induction, algebraic, case_analysis, discharge, reflexivity, unknown. | `PistClassifyTrace.lean` |

## Infrastructure terms

| Term | Definition | Source module |
|------|------------|---------------|
| **Headroom** | Context-compression proxy that shrinks tool outputs before they reach the LLM. | `AGENTS.md` |
| **ContextStream** | Persistent memory / decision graph system (workspace-scoped; currently unavailable in this session). | `AGENTS.md` |
| **cornfield** | Legacy branch / archive state. Retrieve only the named artifact, never merge wholesale. | `AGENTS.md` |
| **quarantine** | A file or module that is kept out of the active build because it is broken, hairy, or not yet ported. | `AGENTS.md` |

---

## How to add or update an entry

1. Add a row to the appropriate table.
2. Make the **Source module** column point at the Lean module, Python shim, or
   `AGENTS.md` section that owns the definition.
3. If the term has a standard name in mathematics, CS, or physics, add it to
   the **Standard terminology crosswalk** and explain the delta.
4. If the term is used in a receipt or gate, ensure the source module proves or
   witnesses the property before the term is promoted.
5. Run `python3 -m py_compile` on any touched Python and `lake build` on any
   touched Lean.

## Draft terms (not yet bound)

Use this section for terms that appear in conversation but do not yet have an
authoritative module definition.

| Term | Notes | Proposed owner |
|------|-------|----------------|
| *none* | — | — |