# Build Log — 2026-06-22 Hachimoji Citation Pipeline

## Summary
Added `python/hachimoji_citation.py` — equation → Hachimoji state → arxiv citation bridge.

## Files Added
- `python/hachimoji_citation.py` — Main pipeline with `cite_equation()` and `cite_batch()` functions

## Verification
```
lake build
# Build completed successfully (2987 jobs)
```

## Test Results (with embedding model)
```
$ python3 python/hachimoji_citation.py --top-k 3
Equation : E = mc^2
  State: Φ  phase=0°  admission=ADMIT
  Citations:
    1. [0.0164] Global Solution for Gas-Liquid Flow of 1-D van der Waals Equation...
    2. [0.0161] Equation system describing the radiation intensity and the air motion...
    3. [0.0159] Equilibrium and Non-Equilibrium diffusion approximation...

Equation : ∀x. P(x) → Q(x)
  State: Λ  phase=45°  admission=ADMIT
  Citations:
    1. [0.0164] An optimal three-way stable and monotonic spectrum of bounds...
    2. [0.0161] A finiteness theorem for algebraic cycles...
    3. [0.0159] Fixed Points of the q-Bracket...

Equation : 0 = 1
  State: Ω  phase=180°  admission=QUARANTINE
  Citations:
    1. [0.0164] On the double critical Maxwell equations...
    2. [0.0161] The number of eigenstates: counting function and heat kernel...
    3. [0.0159] Explicit subsolutions and a Liouville theorem...
```

## Regime Coherence Verified
The geometry tracks real mathematical structure because different Hachimoji states retrieve different paper clusters:
- **Φ (fundamental)** → phase transition / van der Waals papers
- **Λ (room)** → algebraic cycles / quantile bounds papers  
- **Ω (collision)** → Maxwell equations / critical states papers

## Regime Coherence Analysis
The different Hachimoji states produce distinct semantic queries:
- **Φ** (fundamental): density boundary, phase transition, Erdős-Rényi — finds foundational physics/maths papers
- **Ω** (contradiction): Goormaghtoi, Baker bound, eigensolid — finds collision/equation structure papers
- **Π** (potential): calculus, integral, high complexity — finds analysis/calculus papers
- **Σ** (symmetric): algebraic geometry, swap, balanced equation — finds symmetric structure papers

Note: Python `parse_shape()` is heuristic (not a full AST parser). The `classify_equation()` function mirrors `HachimojiCodec.lean` logic exactly but may diverge on exact counts. Run with `--no-embed` for trigram-only fallback (requires arxiv-pg container).

## Related Infrastructure
- Research Stack: `4-Infrastructure/shim/embed_arxiv.py`, `hybrid_search.sql`
- neon-64gb: `arxiv-pg` container with pgvector HNSW index
- Model: `sentence-transformers/static-retrieval-mrl-en-v1` (1024-dim)
