{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2021:A65RBONWZECCTAF574I7NZHMLW","short_pith_number":"pith:A65RBONW","canonical_record":{"source":{"id":"2109.12987","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CL","submitted_at":"2021-09-23T06:10:36Z","cross_cats_sorted":["cs.IR","cs.LG","cs.SI"],"title_canon_sha256":"d614f9f9ddae93370440a9978252da5c99b548a587b0065c6c957f133726421d","abstract_canon_sha256":"1b0c1299d779d542a14b5432c3fdbd3b1ed6754fd0dd04c11d42294bf84c3327"},"schema_version":"1.0"},"canonical_sha256":"07bb10b9b6c9042980bdff11f6e4ec5dbc8f793f3d0a9e83ca7b280366ad84ac","source":{"kind":"arxiv","id":"2109.12987","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2109.12987","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"arxiv_version","alias_value":"2109.12987v1","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2109.12987","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_12","alias_value":"A65RBONWZECC","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_16","alias_value":"A65RBONWZECCTAF5","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_8","alias_value":"A65RBONW","created_at":"2026-07-05T03:17:39Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2021:A65RBONWZECCTAF574I7NZHMLW","target":"record","payload":{"canonical_record":{"source":{"id":"2109.12987","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CL","submitted_at":"2021-09-23T06:10:36Z","cross_cats_sorted":["cs.IR","cs.LG","cs.SI"],"title_canon_sha256":"d614f9f9ddae93370440a9978252da5c99b548a587b0065c6c957f133726421d","abstract_canon_sha256":"1b0c1299d779d542a14b5432c3fdbd3b1ed6754fd0dd04c11d42294bf84c3327"},"schema_version":"1.0"},"canonical_sha256":"07bb10b9b6c9042980bdff11f6e4ec5dbc8f793f3d0a9e83ca7b280366ad84ac","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T03:17:39.837456Z","signature_b64":"I4h+fQhyp6oq3XdSu9DGxRiNvYZQz2VXxtUxQJeUi3G04OeRBUJ/81uyxarhmCGgsJvJlvKS6GclzvvTpYKDBg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"07bb10b9b6c9042980bdff11f6e4ec5dbc8f793f3d0a9e83ca7b280366ad84ac","last_reissued_at":"2026-07-05T03:17:39.836850Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T03:17:39.836850Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2109.12987","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-07-05T03:17:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"XRNabpgXAz+NMLHa4Lh56soAvoLgaglm/z4KTO8DNSY+wZLFEcom/QDwo187+yzJM+Cb31slkTjMfu6lK7/oCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:40:27.775451Z"},"content_sha256":"74ac86ae928e8e8f06d8bd17c671a1740c778262015e6974c0dcf835ff4d7d0c","schema_version":"1.0","event_id":"sha256:74ac86ae928e8e8f06d8bd17c671a1740c778262015e6974c0dcf835ff4d7d0c"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2021:A65RBONWZECCTAF574I7NZHMLW","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Overview of the CLEF--2021 CheckThat! Lab on Detecting Check-Worthy Claims, Previously Fact-Checked Claims, and Fake News","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.IR","cs.LG","cs.SI"],"primary_cat":"cs.CL","authors_text":"Alberto Barr\\'on-Cede\\~no, Alex Nikolov, Bayan Hamdan, Fatima Haouari, Firoj Alam, Gautam Kishore Shahi, Giovanni Da San Martino, Julia Maria Stru{\\ss}, Maram Hasanain, Mucahid Kutlu, Nikolay Babulkov, Preslav Nakov, Rub\\'en M\\'iguez, Shaden Shaar, Tamer Elsayed, Thomas Mandl, Watheq Mansour, Yavuz Selim Kartal, Zien Sheikh Ali","submitted_at":"2021-09-23T06:10:36Z","abstract_excerpt":"We describe the fourth edition of the CheckThat! Lab, part of the 2021 Conference and Labs of the Evaluation Forum (CLEF). The lab evaluates technology supporting tasks related to factuality, and covers Arabic, Bulgarian, English, Spanish, and Turkish. Task 1 asks to predict which posts in a Twitter stream are worth fact-checking, focusing on COVID-19 and politics (in all five languages). Task 2 asks to determine whether a claim in a tweet can be verified using a set of previously fact-checked claims (in Arabic and English). Task 3 asks to predict the veracity of a news article and its topical"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2109.12987","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2109.12987/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"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":"2026-07-05T03:17:39Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ICvOfDlqS5oS/IYg2zFOBPFI7GsZh2fP/eigkx6fGL6AI2YMbwthpR8YYVSaJ7C6Q2zObYOWx+m1BNvdg32sBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-05T11:40:27.775958Z"},"content_sha256":"42efac66e6189dfa406e0e3d86790bea44ec5307f40a2f8e9a381a08b1dbd7d2","schema_version":"1.0","event_id":"sha256:42efac66e6189dfa406e0e3d86790bea44ec5307f40a2f8e9a381a08b1dbd7d2"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/A65RBONWZECCTAF574I7NZHMLW/bundle.json","state_url":"https://pith.science/pith/A65RBONWZECCTAF574I7NZHMLW/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/A65RBONWZECCTAF574I7NZHMLW/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":"2026-08-05T11:40:27Z","links":{"resolver":"https://pith.science/pith/A65RBONWZECCTAF574I7NZHMLW","bundle":"https://pith.science/pith/A65RBONWZECCTAF574I7NZHMLW/bundle.json","state":"https://pith.science/pith/A65RBONWZECCTAF574I7NZHMLW/state.json","well_known_bundle":"https://pith.science/.well-known/pith/A65RBONWZECCTAF574I7NZHMLW/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2021:A65RBONWZECCTAF574I7NZHMLW","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":"1b0c1299d779d542a14b5432c3fdbd3b1ed6754fd0dd04c11d42294bf84c3327","cross_cats_sorted":["cs.IR","cs.LG","cs.SI"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CL","submitted_at":"2021-09-23T06:10:36Z","title_canon_sha256":"d614f9f9ddae93370440a9978252da5c99b548a587b0065c6c957f133726421d"},"schema_version":"1.0","source":{"id":"2109.12987","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2109.12987","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"arxiv_version","alias_value":"2109.12987v1","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2109.12987","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_12","alias_value":"A65RBONWZECC","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_16","alias_value":"A65RBONWZECCTAF5","created_at":"2026-07-05T03:17:39Z"},{"alias_kind":"pith_short_8","alias_value":"A65RBONW","created_at":"2026-07-05T03:17:39Z"}],"graph_snapshots":[{"event_id":"sha256:42efac66e6189dfa406e0e3d86790bea44ec5307f40a2f8e9a381a08b1dbd7d2","target":"graph","created_at":"2026-07-05T03:17:39Z","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"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2109.12987/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We describe the fourth edition of the CheckThat! Lab, part of the 2021 Conference and Labs of the Evaluation Forum (CLEF). The lab evaluates technology supporting tasks related to factuality, and covers Arabic, Bulgarian, English, Spanish, and Turkish. Task 1 asks to predict which posts in a Twitter stream are worth fact-checking, focusing on COVID-19 and politics (in all five languages). Task 2 asks to determine whether a claim in a tweet can be verified using a set of previously fact-checked claims (in Arabic and English). Task 3 asks to predict the veracity of a news article and its topical","authors_text":"Alberto Barr\\'on-Cede\\~no, Alex Nikolov, Bayan Hamdan, Fatima Haouari, Firoj Alam, Gautam Kishore Shahi, Giovanni Da San Martino, Julia Maria Stru{\\ss}, Maram Hasanain, Mucahid Kutlu, Nikolay Babulkov, Preslav Nakov, Rub\\'en M\\'iguez, Shaden Shaar, Tamer Elsayed, Thomas Mandl, Watheq Mansour, Yavuz Selim Kartal, Zien Sheikh Ali","cross_cats":["cs.IR","cs.LG","cs.SI"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CL","submitted_at":"2021-09-23T06:10:36Z","title":"Overview of the CLEF--2021 CheckThat! Lab on Detecting Check-Worthy Claims, Previously Fact-Checked Claims, and Fake News"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2109.12987","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":"sha256:74ac86ae928e8e8f06d8bd17c671a1740c778262015e6974c0dcf835ff4d7d0c","target":"record","created_at":"2026-07-05T03:17:39Z","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":"1b0c1299d779d542a14b5432c3fdbd3b1ed6754fd0dd04c11d42294bf84c3327","cross_cats_sorted":["cs.IR","cs.LG","cs.SI"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CL","submitted_at":"2021-09-23T06:10:36Z","title_canon_sha256":"d614f9f9ddae93370440a9978252da5c99b548a587b0065c6c957f133726421d"},"schema_version":"1.0","source":{"id":"2109.12987","kind":"arxiv","version":1}},"canonical_sha256":"07bb10b9b6c9042980bdff11f6e4ec5dbc8f793f3d0a9e83ca7b280366ad84ac","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"07bb10b9b6c9042980bdff11f6e4ec5dbc8f793f3d0a9e83ca7b280366ad84ac","first_computed_at":"2026-07-05T03:17:39.836850Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T03:17:39.836850Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"I4h+fQhyp6oq3XdSu9DGxRiNvYZQz2VXxtUxQJeUi3G04OeRBUJ/81uyxarhmCGgsJvJlvKS6GclzvvTpYKDBg==","signature_status":"signed_v1","signed_at":"2026-07-05T03:17:39.837456Z","signed_message":"canonical_sha256_bytes"},"source_id":"2109.12987","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:74ac86ae928e8e8f06d8bd17c671a1740c778262015e6974c0dcf835ff4d7d0c","sha256:42efac66e6189dfa406e0e3d86790bea44ec5307f40a2f8e9a381a08b1dbd7d2"],"state_sha256":"763ebaf93095fef1572feaccb5452238940119dbf15249881100368051a40b66"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"Y4gtU1WIp9DqLimM/AnqlX0Qt6GbYAEBNOPpS76Fvn1oDSl50Qvnf7Y5RCyI1Ajag35fgTeKuJvolxfLphvZDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-05T11:40:27.779499Z","bundle_sha256":"8288af0bfc89dd738a3a54f1f356fea69492c49e5d58a2b4d87392b209869b30"}}