{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:XZNADNJ4PUVMJTOKGJH33EUOPQ","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":"b5875223aac5442db1792ac3dd9626c967519680efe2eb580e8f65c67eb11f42","cross_cats_sorted":["cs.DM","cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2019-04-01T16:12:04Z","title_canon_sha256":"5487f244664429d4671119f6f1f46e01516452af6e898bcda689a61587dc3464"},"schema_version":"1.0","source":{"id":"1904.00934","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1904.00934","created_at":"2026-05-17T23:49:44Z"},{"alias_kind":"arxiv_version","alias_value":"1904.00934v1","created_at":"2026-05-17T23:49:44Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1904.00934","created_at":"2026-05-17T23:49:44Z"},{"alias_kind":"pith_short_12","alias_value":"XZNADNJ4PUVM","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"XZNADNJ4PUVMJTOK","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"XZNADNJ4","created_at":"2026-05-18T12:33:33Z"}],"graph_snapshots":[{"event_id":"sha256:e252732aa20839f1d02a25effb61694d46cf047db0a41df41b0f2d2b7c9a87c4","target":"graph","created_at":"2026-05-17T23:49:44Z","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":"Conjunctive query (CQ) evaluation is NP-complete, but becomes tractable for fragments of bounded hypertreewidth. Approximating a hard CQ by a query from such a fragment can thus allow for an efficient approximate evaluation. While underapproximations (i.e., approximations that return correct answers only) are well-understood, the dual notion of overapproximations (i.e, approximations that return complete - but not necessarily sound - answers), and also a more general notion of approximation based on the symmetric difference of query results, are almost unexplored. In fact, the decidability of ","authors_text":"Miguel Romero, Pablo Barcel\\'o, Thomas Zeume","cross_cats":["cs.DM","cs.LO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2019-04-01T16:12:04Z","title":"A More General Theory of Static Approximations for Conjunctive Queries"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1904.00934","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":"sha256:92a069c5211cf54e9a2bc15e8f38d2bb209090e2590eb797308dbe172f93ff72","target":"record","created_at":"2026-05-17T23:49:44Z","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":"b5875223aac5442db1792ac3dd9626c967519680efe2eb580e8f65c67eb11f42","cross_cats_sorted":["cs.DM","cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2019-04-01T16:12:04Z","title_canon_sha256":"5487f244664429d4671119f6f1f46e01516452af6e898bcda689a61587dc3464"},"schema_version":"1.0","source":{"id":"1904.00934","kind":"arxiv","version":1}},"canonical_sha256":"be5a01b53c7d2ac4cdca324fbd928e7c0ea4eaac44cc5bc9a76f2e682eb260db","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"be5a01b53c7d2ac4cdca324fbd928e7c0ea4eaac44cc5bc9a76f2e682eb260db","first_computed_at":"2026-05-17T23:49:44.831081Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:49:44.831081Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"LfUTu2cPtZXi3TyJAELYylOA7dqjyJwM152YrIwqHo6vhoDQ5bPENIEiwroxCjBjm+dI1ol0affk1HwmCK8yCQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:49:44.831613Z","signed_message":"canonical_sha256_bytes"},"source_id":"1904.00934","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:92a069c5211cf54e9a2bc15e8f38d2bb209090e2590eb797308dbe172f93ff72","sha256:e252732aa20839f1d02a25effb61694d46cf047db0a41df41b0f2d2b7c9a87c4"],"state_sha256":"be2f018bb6cf26c2564b3e5ed26ad9bd313131e7773a81bce753f23ea3ec549e"}