{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:UWQCKR4MH2AVRG4SFFBJGQ6J27","short_pith_number":"pith:UWQCKR4M","canonical_record":{"source":{"id":"1312.1672","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-12-05T20:20:06Z","cross_cats_sorted":["cs.DS","cs.LO"],"title_canon_sha256":"a4f41eb88e9a12ff3b59dcad57a77807a757d69808bfa0cb2d510f2b7d678cc2","abstract_canon_sha256":"5257a748f7daa0da7fe24e4d6c07ac8de702cf6d24ec7d587966d2420804af12"},"schema_version":"1.0"},"canonical_sha256":"a5a025478c3e81589b9229429343c9d7fd7fac016d038d9d6e50705e631097f8","source":{"kind":"arxiv","id":"1312.1672","version":4},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1312.1672","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"arxiv_version","alias_value":"1312.1672v4","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1312.1672","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"pith_short_12","alias_value":"UWQCKR4MH2AV","created_at":"2026-05-18T12:28:02Z"},{"alias_kind":"pith_short_16","alias_value":"UWQCKR4MH2AVRG4S","created_at":"2026-05-18T12:28:02Z"},{"alias_kind":"pith_short_8","alias_value":"UWQCKR4M","created_at":"2026-05-18T12:28:02Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:UWQCKR4MH2AVRG4SFFBJGQ6J27","target":"record","payload":{"canonical_record":{"source":{"id":"1312.1672","kind":"arxiv","version":4},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-12-05T20:20:06Z","cross_cats_sorted":["cs.DS","cs.LO"],"title_canon_sha256":"a4f41eb88e9a12ff3b59dcad57a77807a757d69808bfa0cb2d510f2b7d678cc2","abstract_canon_sha256":"5257a748f7daa0da7fe24e4d6c07ac8de702cf6d24ec7d587966d2420804af12"},"schema_version":"1.0"},"canonical_sha256":"a5a025478c3e81589b9229429343c9d7fd7fac016d038d9d6e50705e631097f8","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:11:38.923642Z","signature_b64":"YYD6I/RgK6ua75nSF4BrdR8xbLjqxG/ELpVMjpB3BXD1JAQJXShzI7zAw02wvAiz6VGxE53xlaFD3yFEUH9cDQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a5a025478c3e81589b9229429343c9d7fd7fac016d038d9d6e50705e631097f8","last_reissued_at":"2026-05-18T01:11:38.922969Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:11:38.922969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1312.1672","source_version":4,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:11:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uTTaK8ISEORHQNPrzMgYhKXt8W9qzdRSZV6gnu/ZeQFMkTFexl2KXiz1p1neJ8LFPX40B/sv3Hd9MdUtKTvTDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T20:11:14.591339Z"},"content_sha256":"42bd60c284fe0962b751a1652800549a09110b53e4213c1acfeade34f91e4304","schema_version":"1.0","event_id":"sha256:42bd60c284fe0962b751a1652800549a09110b53e4213c1acfeade34f91e4304"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:UWQCKR4MH2AVRG4SFFBJGQ6J27","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The Parameterized Complexity of Reasoning Problems Beyond NP","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.DS","cs.LO"],"primary_cat":"cs.CC","authors_text":"Ronald de Haan, Stefan Szeider","submitted_at":"2013-12-05T20:20:06Z","abstract_excerpt":"Today's propositional satisfiability (SAT) solvers are extremely powerful and can be used as an efficient back-end for solving NP-complete problems. However, many fundamental problems in knowledge representation and reasoning are located at the second level of the Polynomial Hierarchy or even higher, and hence polynomial-time transformations to SAT are not possible, unless the hierarchy collapses. Recent research shows that in certain cases one can break through these complexity barriers by fixed-parameter tractable (fpt) reductions which exploit structural aspects of problem instances in term"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1312.1672","kind":"arxiv","version":4},"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":"2026-05-18T01:11:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"5/lQ+xMQCJaVXu7uwj0sLtIaWcyVnNuv2l/LHVyF1RuJAdSTCTWSWeeGnc2bCg3deoCs1q6Wd2iZqUFC/Up7Dw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-28T20:11:14.591690Z"},"content_sha256":"ce5c898b44dded6eb2373f53da0a30d1b2582b4c60e1156feae21e204c6045e9","schema_version":"1.0","event_id":"sha256:ce5c898b44dded6eb2373f53da0a30d1b2582b4c60e1156feae21e204c6045e9"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/bundle.json","state_url":"https://pith.science/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/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":"2026-05-28T20:11:14Z","links":{"resolver":"https://pith.science/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27","bundle":"https://pith.science/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/bundle.json","state":"https://pith.science/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/state.json","well_known_bundle":"https://pith.science/.well-known/pith/UWQCKR4MH2AVRG4SFFBJGQ6J27/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:UWQCKR4MH2AVRG4SFFBJGQ6J27","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":"5257a748f7daa0da7fe24e4d6c07ac8de702cf6d24ec7d587966d2420804af12","cross_cats_sorted":["cs.DS","cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-12-05T20:20:06Z","title_canon_sha256":"a4f41eb88e9a12ff3b59dcad57a77807a757d69808bfa0cb2d510f2b7d678cc2"},"schema_version":"1.0","source":{"id":"1312.1672","kind":"arxiv","version":4}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1312.1672","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"arxiv_version","alias_value":"1312.1672v4","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1312.1672","created_at":"2026-05-18T01:11:38Z"},{"alias_kind":"pith_short_12","alias_value":"UWQCKR4MH2AV","created_at":"2026-05-18T12:28:02Z"},{"alias_kind":"pith_short_16","alias_value":"UWQCKR4MH2AVRG4S","created_at":"2026-05-18T12:28:02Z"},{"alias_kind":"pith_short_8","alias_value":"UWQCKR4M","created_at":"2026-05-18T12:28:02Z"}],"graph_snapshots":[{"event_id":"sha256:ce5c898b44dded6eb2373f53da0a30d1b2582b4c60e1156feae21e204c6045e9","target":"graph","created_at":"2026-05-18T01:11:38Z","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":"Today's propositional satisfiability (SAT) solvers are extremely powerful and can be used as an efficient back-end for solving NP-complete problems. However, many fundamental problems in knowledge representation and reasoning are located at the second level of the Polynomial Hierarchy or even higher, and hence polynomial-time transformations to SAT are not possible, unless the hierarchy collapses. Recent research shows that in certain cases one can break through these complexity barriers by fixed-parameter tractable (fpt) reductions which exploit structural aspects of problem instances in term","authors_text":"Ronald de Haan, Stefan Szeider","cross_cats":["cs.DS","cs.LO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-12-05T20:20:06Z","title":"The Parameterized Complexity of Reasoning Problems Beyond NP"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1312.1672","kind":"arxiv","version":4},"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":"sha256:42bd60c284fe0962b751a1652800549a09110b53e4213c1acfeade34f91e4304","target":"record","created_at":"2026-05-18T01:11:38Z","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":"5257a748f7daa0da7fe24e4d6c07ac8de702cf6d24ec7d587966d2420804af12","cross_cats_sorted":["cs.DS","cs.LO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-12-05T20:20:06Z","title_canon_sha256":"a4f41eb88e9a12ff3b59dcad57a77807a757d69808bfa0cb2d510f2b7d678cc2"},"schema_version":"1.0","source":{"id":"1312.1672","kind":"arxiv","version":4}},"canonical_sha256":"a5a025478c3e81589b9229429343c9d7fd7fac016d038d9d6e50705e631097f8","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a5a025478c3e81589b9229429343c9d7fd7fac016d038d9d6e50705e631097f8","first_computed_at":"2026-05-18T01:11:38.922969Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:11:38.922969Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"YYD6I/RgK6ua75nSF4BrdR8xbLjqxG/ELpVMjpB3BXD1JAQJXShzI7zAw02wvAiz6VGxE53xlaFD3yFEUH9cDQ==","signature_status":"signed_v1","signed_at":"2026-05-18T01:11:38.923642Z","signed_message":"canonical_sha256_bytes"},"source_id":"1312.1672","source_kind":"arxiv","source_version":4}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:42bd60c284fe0962b751a1652800549a09110b53e4213c1acfeade34f91e4304","sha256:ce5c898b44dded6eb2373f53da0a30d1b2582b4c60e1156feae21e204c6045e9"],"state_sha256":"9ad1e06b650ddc7a895513e9a4885b9677cd5dee728a4f31473ed76047b3aae1"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Ek5j7A/5dFmc1LpC6H0BllHIDHRIL+M1UV1aD45IB6zIheZ0CL15mbP2jJIrhVMpRveVuSlSKYV1x9NknwlyCA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-28T20:11:14.593894Z","bundle_sha256":"b7ad631630ec6af1d3ae7455228ccd505f2c7562c049c74e21e5875cb930d927"}}