{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:TENXMJL3IUC5MQKEDYX5NBMVJU","short_pith_number":"pith:TENXMJL3","canonical_record":{"source":{"id":"1606.01206","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2016-06-03T18:14:35Z","cross_cats_sorted":["cs.LO"],"title_canon_sha256":"670ac84102309c217d5bcca208ab842d244095fbe552d74b629508400b3f88ec","abstract_canon_sha256":"ec04d094792069b8c9e876f81ca38ab51e7669fdc8278a0278da896c02bc3f16"},"schema_version":"1.0"},"canonical_sha256":"991b76257b4505d641441e2fd685954d06441633cbfc27902062f2bad78c4109","source":{"kind":"arxiv","id":"1606.01206","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1606.01206","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"arxiv_version","alias_value":"1606.01206v2","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1606.01206","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"pith_short_12","alias_value":"TENXMJL3IUC5","created_at":"2026-05-18T12:30:44Z"},{"alias_kind":"pith_short_16","alias_value":"TENXMJL3IUC5MQKE","created_at":"2026-05-18T12:30:44Z"},{"alias_kind":"pith_short_8","alias_value":"TENXMJL3","created_at":"2026-05-18T12:30:44Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:TENXMJL3IUC5MQKEDYX5NBMVJU","target":"record","payload":{"canonical_record":{"source":{"id":"1606.01206","kind":"arxiv","version":2},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2016-06-03T18:14:35Z","cross_cats_sorted":["cs.LO"],"title_canon_sha256":"670ac84102309c217d5bcca208ab842d244095fbe552d74b629508400b3f88ec","abstract_canon_sha256":"ec04d094792069b8c9e876f81ca38ab51e7669fdc8278a0278da896c02bc3f16"},"schema_version":"1.0"},"canonical_sha256":"991b76257b4505d641441e2fd685954d06441633cbfc27902062f2bad78c4109","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:11:22.405974Z","signature_b64":"TreISkXmWKEfUpT2lMNbNB3eLJfipLnzlepgx4V5iPLMwGMVNXpyfD4+SgPQ8DD5Wy6ltmVyxY+skdSfgjeABA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"991b76257b4505d641441e2fd685954d06441633cbfc27902062f2bad78c4109","last_reissued_at":"2026-05-18T01:11:22.405486Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:11:22.405486Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1606.01206","source_version":2,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:11:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"23b195fdNvTrjMzYshpQEi6W5LguadZRG2YN9q6OeCcd7RazBy4TGb2RWP+ptcsrs3I/LyvjinneZIMVv3XHAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T11:43:32.337188Z"},"content_sha256":"b5680f613a8dedbbe8c45ce81d9c5376f96c8276cebcaeac6525788d20006f32","schema_version":"1.0","event_id":"sha256:b5680f613a8dedbbe8c45ce81d9c5376f96c8276cebcaeac6525788d20006f32"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:TENXMJL3IUC5MQKEDYX5NBMVJU","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The complexity of reverse engineering problems for conjunctive queries","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.LO"],"primary_cat":"cs.DB","authors_text":"Miguel Romero, Pablo Barcelo","submitted_at":"2016-06-03T18:14:35Z","abstract_excerpt":"Reverse engineering problems for conjunctive queries (CQs), such as query by example (QBE) or definability, take a set of user examples and convert them into an explanatory CQ. Despite their importance, the complexity of these problems is prohibitively high (coNEXPTIME-complete). We isolate their two main sources of complexity and propose relaxations of them that reduce the complexity while having meaningful theoretical interpretations. The first relaxation is based on the idea of using existential pebble games for approximating homomorphism tests. We show that this characterizes QBE/definabil"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1606.01206","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"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:11:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ueAEPDKTPbwyMKayBSQz5kavkXOknRJp/lpkBfH3tcOMwsnoxipUePxTRLY7oX1Jffy6pSyCU0Y2NrybB3laDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-06T11:43:32.337864Z"},"content_sha256":"c8654286981f99f7b5b1127cf85cf839e688e5ceb5f45eb1f91b4c6e4e901ca9","schema_version":"1.0","event_id":"sha256:c8654286981f99f7b5b1127cf85cf839e688e5ceb5f45eb1f91b4c6e4e901ca9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/bundle.json","state_url":"https://pith.science/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-06-06T11:43:32Z","links":{"resolver":"https://pith.science/pith/TENXMJL3IUC5MQKEDYX5NBMVJU","bundle":"https://pith.science/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/bundle.json","state":"https://pith.science/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/state.json","well_known_bundle":"https://pith.science/.well-known/pith/TENXMJL3IUC5MQKEDYX5NBMVJU/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:TENXMJL3IUC5MQKEDYX5NBMVJU","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":"ec04d094792069b8c9e876f81ca38ab51e7669fdc8278a0278da896c02bc3f16","cross_cats_sorted":["cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2016-06-03T18:14:35Z","title_canon_sha256":"670ac84102309c217d5bcca208ab842d244095fbe552d74b629508400b3f88ec"},"schema_version":"1.0","source":{"id":"1606.01206","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1606.01206","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"arxiv_version","alias_value":"1606.01206v2","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1606.01206","created_at":"2026-05-18T01:11:22Z"},{"alias_kind":"pith_short_12","alias_value":"TENXMJL3IUC5","created_at":"2026-05-18T12:30:44Z"},{"alias_kind":"pith_short_16","alias_value":"TENXMJL3IUC5MQKE","created_at":"2026-05-18T12:30:44Z"},{"alias_kind":"pith_short_8","alias_value":"TENXMJL3","created_at":"2026-05-18T12:30:44Z"}],"graph_snapshots":[{"event_id":"sha256:c8654286981f99f7b5b1127cf85cf839e688e5ceb5f45eb1f91b4c6e4e901ca9","target":"graph","created_at":"2026-05-18T01:11:22Z","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":"Reverse engineering problems for conjunctive queries (CQs), such as query by example (QBE) or definability, take a set of user examples and convert them into an explanatory CQ. Despite their importance, the complexity of these problems is prohibitively high (coNEXPTIME-complete). We isolate their two main sources of complexity and propose relaxations of them that reduce the complexity while having meaningful theoretical interpretations. The first relaxation is based on the idea of using existential pebble games for approximating homomorphism tests. We show that this characterizes QBE/definabil","authors_text":"Miguel Romero, Pablo Barcelo","cross_cats":["cs.LO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2016-06-03T18:14:35Z","title":"The complexity of reverse engineering problems for conjunctive queries"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1606.01206","kind":"arxiv","version":2},"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:b5680f613a8dedbbe8c45ce81d9c5376f96c8276cebcaeac6525788d20006f32","target":"record","created_at":"2026-05-18T01:11:22Z","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":"ec04d094792069b8c9e876f81ca38ab51e7669fdc8278a0278da896c02bc3f16","cross_cats_sorted":["cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.DB","submitted_at":"2016-06-03T18:14:35Z","title_canon_sha256":"670ac84102309c217d5bcca208ab842d244095fbe552d74b629508400b3f88ec"},"schema_version":"1.0","source":{"id":"1606.01206","kind":"arxiv","version":2}},"canonical_sha256":"991b76257b4505d641441e2fd685954d06441633cbfc27902062f2bad78c4109","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"991b76257b4505d641441e2fd685954d06441633cbfc27902062f2bad78c4109","first_computed_at":"2026-05-18T01:11:22.405486Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:11:22.405486Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"TreISkXmWKEfUpT2lMNbNB3eLJfipLnzlepgx4V5iPLMwGMVNXpyfD4+SgPQ8DD5Wy6ltmVyxY+skdSfgjeABA==","signature_status":"signed_v1","signed_at":"2026-05-18T01:11:22.405974Z","signed_message":"canonical_sha256_bytes"},"source_id":"1606.01206","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:b5680f613a8dedbbe8c45ce81d9c5376f96c8276cebcaeac6525788d20006f32","sha256:c8654286981f99f7b5b1127cf85cf839e688e5ceb5f45eb1f91b4c6e4e901ca9"],"state_sha256":"af6d2473e6723361733f9165d84f826b7f6f8f18fa0c342f58913f1ec5c89f4d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"by4okjGE4psORv0ceyhEHkPLIg1wsf1m/yoecTvwdU92rWS89px/7spn0Jy9t+wjTRc8ztxjwQP1a2aMUnWYCQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-06T11:43:32.340594Z","bundle_sha256":"6007f9870bdfea8f3f93bc450cf081dd4d8f54b75b2e34e775f81a1b133a563f"}}