{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2017:7WUES3GHL574FGAUTGQS6ZZ6QJ","short_pith_number":"pith:7WUES3GH","schema_version":"1.0","canonical_sha256":"fda8496cc75f7fc2981499a12f673e8257be462232c5054965d819d6c7b592ef","source":{"kind":"arxiv","id":"1709.09486","version":2},"attestation_state":"computed","paper":{"title":"Surjective H-Colouring over Reflexive Digraphs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.CO"],"primary_cat":"cs.CC","authors_text":"Barnaby Martin, Benoit Larose, Daniel Paulusma","submitted_at":"2017-09-27T13:15:38Z","abstract_excerpt":"The Surjective H-Colouring problem is to test if a given graph allows a vertex-surjective homomorphism to a fixed graph H. The complexity of this problem has been well studied for undirected (partially) reflexive graphs. We introduce endo-triviality, the property of a structure that all of its endomorphisms that do not have range of size 1 are automorphisms, as a means to obtain complexity-theoretic classifications of Surjective H-Colouring in the case of reflexive digraphs.\n  Chen [2014] proved, in the setting of constraint satisfaction problems, that Surjective H-Colouring is NP-complete if "},"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":"1709.09486","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2017-09-27T13:15:38Z","cross_cats_sorted":["math.CO"],"title_canon_sha256":"2aeab9ae36ae18040dc924e0f3c18dd2bb42c2d288f473653acf0af8e700b6fa","abstract_canon_sha256":"d31afe11476370a85d431c8cbb904b00c2b057ac9c637e4380ab54fbbbea94d5"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:27:09.172562Z","signature_b64":"CRWGvDYvJ8dghC1K5ciSvRXFCWnmzN05j0mKFQWLdZHJSHApcsCQ6ZzDDqaqT2i7e+KY+Ug1U0kDFZNqY6OUAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"fda8496cc75f7fc2981499a12f673e8257be462232c5054965d819d6c7b592ef","last_reissued_at":"2026-05-18T00:27:09.172011Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:27:09.172011Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Surjective H-Colouring over Reflexive Digraphs","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.CO"],"primary_cat":"cs.CC","authors_text":"Barnaby Martin, Benoit Larose, Daniel Paulusma","submitted_at":"2017-09-27T13:15:38Z","abstract_excerpt":"The Surjective H-Colouring problem is to test if a given graph allows a vertex-surjective homomorphism to a fixed graph H. The complexity of this problem has been well studied for undirected (partially) reflexive graphs. We introduce endo-triviality, the property of a structure that all of its endomorphisms that do not have range of size 1 are automorphisms, as a means to obtain complexity-theoretic classifications of Surjective H-Colouring in the case of reflexive digraphs.\n  Chen [2014] proved, in the setting of constraint satisfaction problems, that Surjective H-Colouring is NP-complete if "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1709.09486","kind":"arxiv","version":2},"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":"1709.09486","created_at":"2026-05-18T00:27:09.172102+00:00"},{"alias_kind":"arxiv_version","alias_value":"1709.09486v2","created_at":"2026-05-18T00:27:09.172102+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1709.09486","created_at":"2026-05-18T00:27:09.172102+00:00"},{"alias_kind":"pith_short_12","alias_value":"7WUES3GHL574","created_at":"2026-05-18T12:31:05.417338+00:00"},{"alias_kind":"pith_short_16","alias_value":"7WUES3GHL574FGAU","created_at":"2026-05-18T12:31:05.417338+00:00"},{"alias_kind":"pith_short_8","alias_value":"7WUES3GH","created_at":"2026-05-18T12:31:05.417338+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/7WUES3GHL574FGAUTGQS6ZZ6QJ","json":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ.json","graph_json":"https://pith.science/api/pith-number/7WUES3GHL574FGAUTGQS6ZZ6QJ/graph.json","events_json":"https://pith.science/api/pith-number/7WUES3GHL574FGAUTGQS6ZZ6QJ/events.json","paper":"https://pith.science/paper/7WUES3GH"},"agent_actions":{"view_html":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ","download_json":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ.json","view_paper":"https://pith.science/paper/7WUES3GH","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1709.09486&json=true","fetch_graph":"https://pith.science/api/pith-number/7WUES3GHL574FGAUTGQS6ZZ6QJ/graph.json","fetch_events":"https://pith.science/api/pith-number/7WUES3GHL574FGAUTGQS6ZZ6QJ/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ/action/timestamp_anchor","attest_storage":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ/action/storage_attestation","attest_author":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ/action/author_attestation","sign_citation":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ/action/citation_signature","submit_replication":"https://pith.science/pith/7WUES3GHL574FGAUTGQS6ZZ6QJ/action/replication_record"}},"created_at":"2026-05-18T00:27:09.172102+00:00","updated_at":"2026-05-18T00:27:09.172102+00:00"}