{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2025:ZUK2224JBXL2I2UWPSW55TSIZ6","short_pith_number":"pith:ZUK2224J","canonical_record":{"source":{"id":"2505.11693","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CL","submitted_at":"2025-05-16T21:01:28Z","cross_cats_sorted":[],"title_canon_sha256":"353514f22555c626afc0b324d1394c06338601620306f43ae8115dc47dd260ab","abstract_canon_sha256":"3e051bf712f9a93e99ada989600b03baaf226e028b1cd28f591c690e8fe3d219"},"schema_version":"1.0"},"canonical_sha256":"cd15ad6b890dd7a46a967caddece48cfb513ce1d2b990659c05b933241577068","source":{"kind":"arxiv","id":"2505.11693","version":2},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.11693","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"arxiv_version","alias_value":"2505.11693v2","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.11693","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_12","alias_value":"ZUK2224JBXL2","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_16","alias_value":"ZUK2224JBXL2I2UW","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_8","alias_value":"ZUK2224J","created_at":"2026-07-05T11:34:51Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2025:ZUK2224JBXL2I2UWPSW55TSIZ6","target":"record","payload":{"canonical_record":{"source":{"id":"2505.11693","kind":"arxiv","version":2},"metadata":{"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CL","submitted_at":"2025-05-16T21:01:28Z","cross_cats_sorted":[],"title_canon_sha256":"353514f22555c626afc0b324d1394c06338601620306f43ae8115dc47dd260ab","abstract_canon_sha256":"3e051bf712f9a93e99ada989600b03baaf226e028b1cd28f591c690e8fe3d219"},"schema_version":"1.0"},"canonical_sha256":"cd15ad6b890dd7a46a967caddece48cfb513ce1d2b990659c05b933241577068","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T11:34:51.186287Z","signature_b64":"U2bF9QIv5QftzLCPqDVGCc17F8L4LLIntaRj7pb9vJ+Oug0AnUWcPOwpr+kMIZdUFSNKHM02UDh3oUYUwrjABw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"cd15ad6b890dd7a46a967caddece48cfb513ce1d2b990659c05b933241577068","last_reissued_at":"2026-07-05T11:34:51.185749Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T11:34:51.185749Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2505.11693","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":"2026-07-05T11:34:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"iURjGq3f2I4qE3w8DO2yJwAF+ZU/rkviVyOw/56qnnMbjuN/i/DribKPWWYL9RtSKuHo/DRbKO76QO5LopvpAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-23T11:30:01.581001Z"},"content_sha256":"cbca1a357e087dbc5dc4e79f13c61f95a3eb9ae9aa88bb3f7b54f8cd39cf4b07","schema_version":"1.0","event_id":"sha256:cbca1a357e087dbc5dc4e79f13c61f95a3eb9ae9aa88bb3f7b54f8cd39cf4b07"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2025:ZUK2224JBXL2I2UWPSW55TSIZ6","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Hierarchical Bracketing Encodings for Dependency Parsing as Tagging","license":"http://creativecommons.org/licenses/by/4.0/","headline":"","cross_cats":[],"primary_cat":"cs.CL","authors_text":"Ana Ezquerro, Anssi Yli-Jyr\\\"a, Carlos G\\'omez-Rodr\\'iguez, David Vilares","submitted_at":"2025-05-16T21:01:28Z","abstract_excerpt":"We present a family of encodings for sequence labeling dependency parsing, based on the concept of hierarchical bracketing. We prove that the existing 4-bit projective encoding belongs to this family, but it is suboptimal in the number of labels used to encode a tree. We derive an optimal hierarchical bracketing, which minimizes the number of symbols used and encodes projective trees using only 12 distinct labels (vs. 16 for the 4-bit encoding). We also extend optimal hierarchical bracketing to support arbitrary non-projectivity in a more compact way than previous encodings. Our new encodings "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.11693","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2505.11693/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":"2026-07-05T11:34:51Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"ctvzCyNpEq07zKTjzwIq7C0lN6tmqWd5+Om/WIOE0phAjV2R4Ju3EzV0K+ORL1akbH0+9W+C69EcV9LV8+P0Ag==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-23T11:30:01.581673Z"},"content_sha256":"5a0d57fd486a83a4eafc94653bdc84f989aeb2ea11d35d59ea50276845f46aa8","schema_version":"1.0","event_id":"sha256:5a0d57fd486a83a4eafc94653bdc84f989aeb2ea11d35d59ea50276845f46aa8"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/bundle.json","state_url":"https://pith.science/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/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":"2026-08-23T11:30:01Z","links":{"resolver":"https://pith.science/pith/ZUK2224JBXL2I2UWPSW55TSIZ6","bundle":"https://pith.science/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/bundle.json","state":"https://pith.science/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/state.json","well_known_bundle":"https://pith.science/.well-known/pith/ZUK2224JBXL2I2UWPSW55TSIZ6/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2025:ZUK2224JBXL2I2UWPSW55TSIZ6","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":"3e051bf712f9a93e99ada989600b03baaf226e028b1cd28f591c690e8fe3d219","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CL","submitted_at":"2025-05-16T21:01:28Z","title_canon_sha256":"353514f22555c626afc0b324d1394c06338601620306f43ae8115dc47dd260ab"},"schema_version":"1.0","source":{"id":"2505.11693","kind":"arxiv","version":2}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2505.11693","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"arxiv_version","alias_value":"2505.11693v2","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2505.11693","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_12","alias_value":"ZUK2224JBXL2","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_16","alias_value":"ZUK2224JBXL2I2UW","created_at":"2026-07-05T11:34:51Z"},{"alias_kind":"pith_short_8","alias_value":"ZUK2224J","created_at":"2026-07-05T11:34:51Z"}],"graph_snapshots":[{"event_id":"sha256:5a0d57fd486a83a4eafc94653bdc84f989aeb2ea11d35d59ea50276845f46aa8","target":"graph","created_at":"2026-07-05T11:34:51Z","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/2505.11693/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We present a family of encodings for sequence labeling dependency parsing, based on the concept of hierarchical bracketing. We prove that the existing 4-bit projective encoding belongs to this family, but it is suboptimal in the number of labels used to encode a tree. We derive an optimal hierarchical bracketing, which minimizes the number of symbols used and encodes projective trees using only 12 distinct labels (vs. 16 for the 4-bit encoding). We also extend optimal hierarchical bracketing to support arbitrary non-projectivity in a more compact way than previous encodings. Our new encodings ","authors_text":"Ana Ezquerro, Anssi Yli-Jyr\\\"a, Carlos G\\'omez-Rodr\\'iguez, David Vilares","cross_cats":[],"headline":"","license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CL","submitted_at":"2025-05-16T21:01:28Z","title":"Hierarchical Bracketing Encodings for Dependency Parsing as Tagging"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2505.11693","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:cbca1a357e087dbc5dc4e79f13c61f95a3eb9ae9aa88bb3f7b54f8cd39cf4b07","target":"record","created_at":"2026-07-05T11:34:51Z","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":"3e051bf712f9a93e99ada989600b03baaf226e028b1cd28f591c690e8fe3d219","cross_cats_sorted":[],"license":"http://creativecommons.org/licenses/by/4.0/","primary_cat":"cs.CL","submitted_at":"2025-05-16T21:01:28Z","title_canon_sha256":"353514f22555c626afc0b324d1394c06338601620306f43ae8115dc47dd260ab"},"schema_version":"1.0","source":{"id":"2505.11693","kind":"arxiv","version":2}},"canonical_sha256":"cd15ad6b890dd7a46a967caddece48cfb513ce1d2b990659c05b933241577068","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"cd15ad6b890dd7a46a967caddece48cfb513ce1d2b990659c05b933241577068","first_computed_at":"2026-07-05T11:34:51.185749Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T11:34:51.185749Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"U2bF9QIv5QftzLCPqDVGCc17F8L4LLIntaRj7pb9vJ+Oug0AnUWcPOwpr+kMIZdUFSNKHM02UDh3oUYUwrjABw==","signature_status":"signed_v1","signed_at":"2026-07-05T11:34:51.186287Z","signed_message":"canonical_sha256_bytes"},"source_id":"2505.11693","source_kind":"arxiv","source_version":2}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:cbca1a357e087dbc5dc4e79f13c61f95a3eb9ae9aa88bb3f7b54f8cd39cf4b07","sha256:5a0d57fd486a83a4eafc94653bdc84f989aeb2ea11d35d59ea50276845f46aa8"],"state_sha256":"4a3dd6bc27e53290e1481fa87dd952f3197be3b054e4844d87a8b823da4485b9"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WMysq6GRrRllhz4dC5cqDcYu2jrkKGVhIiTlhhPRXVFB0eGtTD1knNMBSbtvvRg8enykb2wvLiVm+yYKTn4zDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-23T11:30:01.587164Z","bundle_sha256":"44a1bfef75b459d93617b71cc31b7fda410c9aee367229e116c2d1d071316953"}}