{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2008:KWGFZ7Q75PV456B6UHUBGFY7EA","short_pith_number":"pith:KWGFZ7Q7","schema_version":"1.0","canonical_sha256":"558c5cfe1febebcef83ea1e813171f202141d241c62da1c813a948ea9d53f2db","source":{"kind":"arxiv","id":"0812.1061","version":6},"attestation_state":"computed","paper":{"title":"Decidability of the Equivalence of Multi-Letter Quantum Finite Automata","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.CC"],"primary_cat":"cs.FL","authors_text":"Daowen Qiu, Lvzhou Li, Paulo Mateus, Xiangfu Zou","submitted_at":"2008-12-05T00:53:20Z","abstract_excerpt":"Multi-letter {\\it quantum finite automata} (QFAs) were a quantum variant of classical {\\it one-way multi-head finite automata} (J. Hromkovi\\v{c}, Acta Informatica 19 (1983) 377-384), and it has been shown that this new one-way QFAs (multi-letter QFAs) can accept with no error some regular languages $(a+b)^{*}b$ that are unacceptable by the previous one-way QFAs. In this paper, we study the decidability of the equivalence of multi-letter QFAs, and the main technical contributions are as follows: (1) We show that any two automata, a $k_{1}$-letter QFA ${\\cal A}_1$ and a $k_{2}$-letter QFA ${\\cal"},"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":"0812.1061","kind":"arxiv","version":6},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2008-12-05T00:53:20Z","cross_cats_sorted":["cs.CC"],"title_canon_sha256":"8969b868f9286a1a40261a5ea3b2f965d7739dbb52d7596ecdec3c3a9ce91aae","abstract_canon_sha256":"18f148f0b7a9b9d4dba8b96c9b5a632e2c523d55e60e74b971466e30d541bee4"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T04:38:14.483015Z","signature_b64":"Hp1Rz6l0Ft0lQSK3gTSUBpmoQ/BnidFzR7ErxovLspIlDnbO+u1jomxBfi6SF4IValKpYGxMesmMmWkvah5QBQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"558c5cfe1febebcef83ea1e813171f202141d241c62da1c813a948ea9d53f2db","last_reissued_at":"2026-05-18T04:38:14.482520Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T04:38:14.482520Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"Decidability of the Equivalence of Multi-Letter Quantum Finite Automata","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.CC"],"primary_cat":"cs.FL","authors_text":"Daowen Qiu, Lvzhou Li, Paulo Mateus, Xiangfu Zou","submitted_at":"2008-12-05T00:53:20Z","abstract_excerpt":"Multi-letter {\\it quantum finite automata} (QFAs) were a quantum variant of classical {\\it one-way multi-head finite automata} (J. Hromkovi\\v{c}, Acta Informatica 19 (1983) 377-384), and it has been shown that this new one-way QFAs (multi-letter QFAs) can accept with no error some regular languages $(a+b)^{*}b$ that are unacceptable by the previous one-way QFAs. In this paper, we study the decidability of the equivalence of multi-letter QFAs, and the main technical contributions are as follows: (1) We show that any two automata, a $k_{1}$-letter QFA ${\\cal A}_1$ and a $k_{2}$-letter QFA ${\\cal"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"0812.1061","kind":"arxiv","version":6},"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":"0812.1061","created_at":"2026-05-18T04:38:14.482598+00:00"},{"alias_kind":"arxiv_version","alias_value":"0812.1061v6","created_at":"2026-05-18T04:38:14.482598+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.0812.1061","created_at":"2026-05-18T04:38:14.482598+00:00"},{"alias_kind":"pith_short_12","alias_value":"KWGFZ7Q75PV4","created_at":"2026-05-18T12:25:57.157939+00:00"},{"alias_kind":"pith_short_16","alias_value":"KWGFZ7Q75PV456B6","created_at":"2026-05-18T12:25:57.157939+00:00"},{"alias_kind":"pith_short_8","alias_value":"KWGFZ7Q7","created_at":"2026-05-18T12:25:57.157939+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/KWGFZ7Q75PV456B6UHUBGFY7EA","json":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA.json","graph_json":"https://pith.science/api/pith-number/KWGFZ7Q75PV456B6UHUBGFY7EA/graph.json","events_json":"https://pith.science/api/pith-number/KWGFZ7Q75PV456B6UHUBGFY7EA/events.json","paper":"https://pith.science/paper/KWGFZ7Q7"},"agent_actions":{"view_html":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA","download_json":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA.json","view_paper":"https://pith.science/paper/KWGFZ7Q7","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=0812.1061&json=true","fetch_graph":"https://pith.science/api/pith-number/KWGFZ7Q75PV456B6UHUBGFY7EA/graph.json","fetch_events":"https://pith.science/api/pith-number/KWGFZ7Q75PV456B6UHUBGFY7EA/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA/action/timestamp_anchor","attest_storage":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA/action/storage_attestation","attest_author":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA/action/author_attestation","sign_citation":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA/action/citation_signature","submit_replication":"https://pith.science/pith/KWGFZ7Q75PV456B6UHUBGFY7EA/action/replication_record"}},"created_at":"2026-05-18T04:38:14.482598+00:00","updated_at":"2026-05-18T04:38:14.482598+00:00"}