From ce4801e8a370b1d0e75fea10dfa8d86a022b42f5 Mon Sep 17 00:00:00 2001
From: Rodin <rodin@foredthought.ai>
Date: Sat, 9 May 2026 23:35:36 -0700
Subject: [PATCH] Add Finding #62: Boundary contract analysis (new analytical
 lens)
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Tested on signal-lifecycle.md (111 lines). Results:
- GPT-5: 17 gaps (7,744 reasoning tokens)
- Opus: 11 gaps (design-level focus)
- Sonnet: 8 gaps (fastest, protocol-level)

Key insight: Union of all models (~26 gaps) far exceeds any single
model (max 17). Only 5 gaps found by all three — highly differentiated
outputs make multi-model runs valuable for interface documents.
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+# Boundary Contract Analysis — Finding #62
+
+**Date:** 2026-05-10  
+**Lens:** Boundary Contract Analysis (NEW)  
+**Document:** gargoyle's `signal-lifecycle.md` (111 lines)  
+**Models:** GPT-5, Claude Opus 4, Claude Sonnet 4
+
+## Summary
+
+New analytical lens that examines implicit contracts at component interfaces — what one component promises/expects that another must deliver/understand. Unlike assumption-finding (what must be true) or race condition analysis (temporal interleavings), this focuses specifically on INTERFACE ASSUMPTIONS.
+
+## Results
+
+| Model | Time | Output tokens | Reasoning tokens | Gaps found | Critical | High |
+|---|---|---|---|---|---|---|
+| GPT-5 | 125s | 2,062 | 7,744 | 17 | 5 | 4 |
+| Claude Opus 4 | ~74s | 2,243 | (internal) | 11 | 3 | 4 |
+| Claude Sonnet 4 | ~40s | 947 | (internal) | 8 | 2 | 3 |
+
+## Key Findings
+
+### Common Ground (all 3 found)
+- Action normalization responsibility and position state dependency (CRITICAL)
+- Instrument ID resolution timing across corporate actions
+- stop_loss semantic transfer from signal to PortfolioMonitor
+- Quantity/units interpretation for options vs stocks (100x sizing error)
+- Audit log write failure handling
+
+### GPT-5 Unique (5 most significant)
+1. **Signal fan-out double-execution** (CRITICAL) — "one signal can appear under many decisions" creates execution-level hazard with no dedupe contract
+2. **Signal replay/dedup gap** — pipeline processes duplicates normally, only audit-level symptoms
+3. **Instrument resolution trust boundary** — wrong-but-known instrument_id passes through
+4. **Late-arriving signals silently re-grouped** — no notification or audit
+5. **Ticker vs instrument_id mismatch** — misleading observability
+
+### Opus Unique
+1. **Entry price reconciliation** — multiple signals with different entry_prices aggregate; which wins?
+2. **Aggregator group identification key** — not specified in signal fields
+3. **Backpressure expiration criteria** — FIFO without priority could drop risk-critical signals
+
+### Sonnet Unique
+1. **Signal ordering contract** — close signal could arrive before buy signal
+2. **Signal ID generation entropy** — poor entropy could cause collisions
+
+## Model Strengths for This Lens
+
+| Model | Strength | Best For |
+|---|---|---|
+| GPT-5 | Exhaustive validation gap enumeration | Comprehensive boundary audits |
+| Opus | Design-level incompleteness | "Model is fundamentally underspecified" |
+| Sonnet | Protocol/temporal assumptions | Quick first-pass screening |
+
+## Key Insight
+
+The union of all findings (~26 distinct gaps) significantly exceeds any single model's output (17, 11, 8). Only 5 gaps were found by all three models. This lens produces highly differentiated outputs across models — run all three for architecture documents describing component interfaces.
+
+## Practical Application
+
+For documents that describe component interfaces, boundary contract analysis is high-value:
+1. Run Sonnet first for quick temporal/protocol screening (40s, cheap)
+2. Run GPT-5 for exhaustive validation/semantic gaps (125s, thorough)
+3. Run Opus for design-level coherence gaps (74s, insightful)
+
+The combination catches significantly more issues than any single pass.