{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:64JRWJTK43D7LWWEDINZLS5JPC","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"ae451e079daf20e07196e732fdb19cda6435bd1aead7c387ee5674ffc659524e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2025-07-22T22:32:30Z","title_canon_sha256":"10f58a134f8d3be16c41450399805aade90a558ab78abfe1c1e8e29782130cdb"},"schema_version":"1.0","source":{"id":"2507.21137","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2507.21137","created_at":"2026-07-05T11:44:31Z"},{"alias_kind":"arxiv_version","alias_value":"2507.21137v1","created_at":"2026-07-05T11:44:31Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2507.21137","created_at":"2026-07-05T11:44:31Z"},{"alias_kind":"pith_short_12","alias_value":"64JRWJTK43D7","created_at":"2026-07-05T11:44:31Z"},{"alias_kind":"pith_short_16","alias_value":"64JRWJTK43D7LWWE","created_at":"2026-07-05T11:44:31Z"},{"alias_kind":"pith_short_8","alias_value":"64JRWJTK","created_at":"2026-07-05T11:44:31Z"}],"graph_snapshots":[{"event_id":"sha256:c44d550a8fe9d53b7d073e39e20df40645774d3635b974701dd28a36404138d2","target":"graph","created_at":"2026-07-05T11:44:31Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2507.21137/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"In this paper we try to answer the question \"What constitutes Sudoku difficulty rating across different Sudoku websites?\" Using two distinct methods that can both solve every Sudoku puzzle, I propose two new metrics to characterize Sudoku difficulty. The first method is based on converting a Sudoku puzzle into its corresponding Satisfiability (SAT) problem. The first proposed metric is derived from SAT Clause Length Distribution which captures the structural complexity of a Sudoku puzzle including the number of given digits and the cells they are in. The second method simulates human Sudoku so","authors_text":"Arman Eisenkolb-Vaithyanathan","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2025-07-22T22:32:30Z","title":"Project Patti: Why can You Solve Diabolical Puzzles on one Sudoku Website but not Easy Puzzles on another Sudoku Website?"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2507.21137","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:08ec08b161f23ae8ea0b7070962262a7fc0f04196d139b0dbdab7d4b6e091301","target":"record","created_at":"2026-07-05T11:44:31Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"ae451e079daf20e07196e732fdb19cda6435bd1aead7c387ee5674ffc659524e","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2025-07-22T22:32:30Z","title_canon_sha256":"10f58a134f8d3be16c41450399805aade90a558ab78abfe1c1e8e29782130cdb"},"schema_version":"1.0","source":{"id":"2507.21137","kind":"arxiv","version":1}},"canonical_sha256":"f7131b266ae6c7f5dac41a1b95cba978a1324f18174219598b5c7345494466c7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"f7131b266ae6c7f5dac41a1b95cba978a1324f18174219598b5c7345494466c7","first_computed_at":"2026-07-05T11:44:31.886773Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:44:31.886773Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"tMvz44n2qdfqgdo0FYmZXbe3ONRiZNY8R8g4eP98iQ8fpCVLj3YI2Ks/aBbh6isoFtL+71rvzJii6x3VmuO0Bg==","signature_status":"signed_v1","signed_at":"2026-07-05T11:44:31.887164Z","signed_message":"canonical_sha256_bytes"},"source_id":"2507.21137","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:08ec08b161f23ae8ea0b7070962262a7fc0f04196d139b0dbdab7d4b6e091301","sha256:c44d550a8fe9d53b7d073e39e20df40645774d3635b974701dd28a36404138d2"],"state_sha256":"d661198539f2dbcf3fd3e2f254440839d80d60a797bc8ca70741b80d510b2a66"}