{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:KQGUQNB4WLROMCI2G2EBXU5ODQ","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":"09f358b7b8163ffe93c7824b99c7c8d3ff22457771dd090c05a07f72d65deaf4","cross_cats_sorted":["cs.LG"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2013-01-23T15:57:30Z","title_canon_sha256":"b6a475e7f74819aa5274578c3a923fd7346a1391bde24f7e462efab6ba1f5565"},"schema_version":"1.0","source":{"id":"1301.6688","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1301.6688","created_at":"2026-05-18T03:35:13Z"},{"alias_kind":"arxiv_version","alias_value":"1301.6688v1","created_at":"2026-05-18T03:35:13Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1301.6688","created_at":"2026-05-18T03:35:13Z"},{"alias_kind":"pith_short_12","alias_value":"KQGUQNB4WLRO","created_at":"2026-05-18T12:27:51Z"},{"alias_kind":"pith_short_16","alias_value":"KQGUQNB4WLROMCI2","created_at":"2026-05-18T12:27:51Z"},{"alias_kind":"pith_short_8","alias_value":"KQGUQNB4","created_at":"2026-05-18T12:27:51Z"}],"graph_snapshots":[{"event_id":"sha256:31660cb4ae8a88db55a34994f1a0b4c64eb730f5aed26bf8f2eee754857d20aa","target":"graph","created_at":"2026-05-18T03:35:13Z","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"},"paper":{"abstract_excerpt":"We consider the task of learning the maximum-likelihood polytree from data. Our first result is a performance guarantee establishing that the optimal branching (or Chow-Liu tree), which can be computed very easily, constitutes a good approximation to the best polytree. We then show that it is not possible to do very much better, since the learning problem is NP-hard even to approximately solve within some constant factor.","authors_text":"Sanjoy Dasgupta","cross_cats":["cs.LG"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2013-01-23T15:57:30Z","title":"Learning Polytrees"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1301.6688","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":"sha256:36437dc4b9d682e6e55dafc44db162d174d99eb001dc693fbd30b9eb2b3a43e3","target":"record","created_at":"2026-05-18T03:35:13Z","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":"09f358b7b8163ffe93c7824b99c7c8d3ff22457771dd090c05a07f72d65deaf4","cross_cats_sorted":["cs.LG"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.AI","submitted_at":"2013-01-23T15:57:30Z","title_canon_sha256":"b6a475e7f74819aa5274578c3a923fd7346a1391bde24f7e462efab6ba1f5565"},"schema_version":"1.0","source":{"id":"1301.6688","kind":"arxiv","version":1}},"canonical_sha256":"540d48343cb2e2e6091a36881bd3ae1c125a8bad1a19208f901ddc85a953d08f","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"540d48343cb2e2e6091a36881bd3ae1c125a8bad1a19208f901ddc85a953d08f","first_computed_at":"2026-05-18T03:35:13.009941Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:35:13.009941Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"n3XSj27Wc8irgjh5YNGyFNcdXNeQRdQlFCevqTnA6/CRgsulR2oPLFvvctL3+9JPlxtBp8Lr/zr3FSIHH3KMBg==","signature_status":"signed_v1","signed_at":"2026-05-18T03:35:13.010483Z","signed_message":"canonical_sha256_bytes"},"source_id":"1301.6688","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:36437dc4b9d682e6e55dafc44db162d174d99eb001dc693fbd30b9eb2b3a43e3","sha256:31660cb4ae8a88db55a34994f1a0b4c64eb730f5aed26bf8f2eee754857d20aa"],"state_sha256":"27e05dbe2808a0b693a2ce71d200f407c42acd8a8fbb546f7c574ae4b7988538"}