{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2019:37YIWGVLSVPCZ7SQPK255KDLIE","short_pith_number":"pith:37YIWGVL","schema_version":"1.0","canonical_sha256":"dff08b1aab955e2cfe507ab5dea86b412361814862a4f226b5dd4f892d2a638f","source":{"kind":"arxiv","id":"1906.05638","version":1},"attestation_state":"computed","paper":{"title":"On the 4-color theorem for signed graphs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.CO","authors_text":"Franti\\v{s}ek Kardo\\v{s}, Jonathan Narboni","submitted_at":"2019-06-13T12:50:27Z","abstract_excerpt":"There are several ways to generalize graph coloring to signed graphs. M\\'a\\v{c}ajov\\'a, Raspaud and \\v{S}koviera introduced one of them and conjectured that in this setting, for signed planar graphs four colors are always enough, generalising thereby The Four Color Theorem. We disprove the conjecture."},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1906.05638","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.CO","submitted_at":"2019-06-13T12:50:27Z","cross_cats_sorted":[],"title_canon_sha256":"40d01958c011bd118c325ba237ab3018a4849b4160d553405297d958796e7541","abstract_canon_sha256":"d7ac0384be93eaed72dc22aa03279fb0d244fabd45fa1df7bb9d03f7099b2b33"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:43:24.761408Z","signature_b64":"jeuXJzIXuQL4rox9UK9aaQfOgAPt/xVrJ+QDyrDIRJRSwxk/OHyf+1rRgbxY/OaQmK8GheSos1CouT9iHoetAg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"dff08b1aab955e2cfe507ab5dea86b412361814862a4f226b5dd4f892d2a638f","last_reissued_at":"2026-05-17T23:43:24.760829Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:43:24.760829Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"On the 4-color theorem for signed graphs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"math.CO","authors_text":"Franti\\v{s}ek Kardo\\v{s}, Jonathan Narboni","submitted_at":"2019-06-13T12:50:27Z","abstract_excerpt":"There are several ways to generalize graph coloring to signed graphs. M\\'a\\v{c}ajov\\'a, Raspaud and \\v{S}koviera introduced one of them and conjectured that in this setting, for signed planar graphs four colors are always enough, generalising thereby The Four Color Theorem. We disprove the conjecture."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1906.05638","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"aliases":[{"alias_kind":"arxiv","alias_value":"1906.05638","created_at":"2026-05-17T23:43:24.760896+00:00"},{"alias_kind":"arxiv_version","alias_value":"1906.05638v1","created_at":"2026-05-17T23:43:24.760896+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1906.05638","created_at":"2026-05-17T23:43:24.760896+00:00"},{"alias_kind":"pith_short_12","alias_value":"37YIWGVLSVPC","created_at":"2026-05-18T12:33:07.085635+00:00"},{"alias_kind":"pith_short_16","alias_value":"37YIWGVLSVPCZ7SQ","created_at":"2026-05-18T12:33:07.085635+00:00"},{"alias_kind":"pith_short_8","alias_value":"37YIWGVL","created_at":"2026-05-18T12:33:07.085635+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE","json":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE.json","graph_json":"https://pith.science/api/pith-number/37YIWGVLSVPCZ7SQPK255KDLIE/graph.json","events_json":"https://pith.science/api/pith-number/37YIWGVLSVPCZ7SQPK255KDLIE/events.json","paper":"https://pith.science/paper/37YIWGVL"},"agent_actions":{"view_html":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE","download_json":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE.json","view_paper":"https://pith.science/paper/37YIWGVL","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1906.05638&json=true","fetch_graph":"https://pith.science/api/pith-number/37YIWGVLSVPCZ7SQPK255KDLIE/graph.json","fetch_events":"https://pith.science/api/pith-number/37YIWGVLSVPCZ7SQPK255KDLIE/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE/action/timestamp_anchor","attest_storage":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE/action/storage_attestation","attest_author":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE/action/author_attestation","sign_citation":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE/action/citation_signature","submit_replication":"https://pith.science/pith/37YIWGVLSVPCZ7SQPK255KDLIE/action/replication_record"}},"created_at":"2026-05-17T23:43:24.760896+00:00","updated_at":"2026-05-17T23:43:24.760896+00:00"}