The Fibonacci sequence first appeared in Western mathematics in the book "Liber Abaci" in 1202.

**Cycle ID:** `cycle_8807_cyc_8807_54396931` **Verified at:** 2026-04-12T21:05:36.583Z **Ensemble:** 9 models from 3 providers **Result:** 9 of 9 models responded **Cycle wall time:** 19.269 seconds **Canonical URL:** https://trust.polylogicai.com/claim/the-fibonacci-sequence-first-appeared-in-western-mathematics-in-the-book-liber-a **Source paper:** [PolybrainBench (version 12)](https://trust.polylogicai.com/polybrainbench) **Source ledger row:** [`public-ledger.jsonl#cycle_8807_cyc_8807_54396931`](https://huggingface.co/datasets/polylogic/polybrainbench/blob/main/public-ledger.jsonl) **Cryptographic provenance:** SHA-256 `3fbb8102d1bdef44631b82fb6d60f9fb7ccbfce986b47eec9f42ba5062f5ad1f`

Verification verdict

Of 9 models in the ensemble, 9 responded successfully and 0 failed.

Per-model responses

The full text of each model's response is available in the source ledger. The summary below records each model's success or failure and the first 280 characters of its response.

| Model | Status | Response chars | | --- | :---: | ---: | | gpt-4.1-mini | ✓ | 1038 | | gpt-4.1-nano | ✓ | 2658 | | gpt-oss-120b | ✓ | 2801 | | grok-3-mini | ✓ | 6543 | | grok-4-fast | ✓ | 6603 | | kimi-k2-groq | ✓ | 675 | | llama-3.3-70b | ✓ | 1820 | | llama-4-scout | ✓ | 1909 | | qwen3-32b | ✓ | 6717 |

Pairwise agreement

The pairwise Jaccard agreement between successful responses for this cycle:

_Per-cycle pairwise agreement matrix is computed offline; will be populated in canonical page v2._

Divergence score

This cycle's divergence score is **TBD** on a 0 to 1 scale, where 0 means all responses are token-identical and 1 means no two responses share any tokens. The dataset-wide median divergence is 0.5 for context.

How to cite this claim

```bibtex @misc{polybrainbench_claim_cycle_8807_cyc_8807_54396931, author = {Polylogic AI}, title = {The Fibonacci sequence first appeared in Western mathematics in the book "Liber Abaci" in 1202.}, year = {2026}, howpublished = {PolybrainBench cycle cycle_8807_cyc_8807_54396931}, url = {https://trust.polylogicai.com/claim/the-fibonacci-sequence-first-appeared-in-western-mathematics-in-the-book-liber-a} } ```

Reproduce this cycle

```bash node ~/polybrain/bin/polybrain-cycle.mjs start --raw --fast "The Fibonacci sequence first appeared in Western mathematics in the book "Liber Abaci" in 1202." ```

Schema.org structured data

```json { "@context": "https://schema.org", "@type": "ClaimReview", "datePublished": "2026-04-12T21:05:36.583Z", "url": "https://trust.polylogicai.com/claim/the-fibonacci-sequence-first-appeared-in-western-mathematics-in-the-book-liber-a", "claimReviewed": "The Fibonacci sequence first appeared in Western mathematics in the book \"Liber Abaci\" in 1202.", "itemReviewed": { "@type": "Claim", "datePublished": "2026-04-12T21:05:36.583Z", "appearance": "https://trust.polylogicai.com/claim/the-fibonacci-sequence-first-appeared-in-western-mathematics-in-the-book-liber-a", "author": { "@type": "Organization", "name": "PolybrainBench" } }, "reviewRating": { "@type": "Rating", "ratingValue": "9", "bestRating": "9", "worstRating": "0", "alternateName": "Unanimous" }, "author": { "@type": "Organization", "name": "Polylogic AI", "url": "https://polylogicai.com" } } ```

Provenance and integrity

This page was generated by the PolybrainBench daemon at version 0.1.0 from cycle cycle_8807_cyc_8807_54396931. The full provenance chain (per-response SHA-256 stamps, cross-cycle prev-hash linking, Thalamus grounding verification) is recorded in the source cycle directory at `~/polybrain/cycles/8807/provenance.json` and mirrored in the published dataset. The page is regenerated on every harvest pass; the URL is permanent and the content is immutable for any given paper version.