{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:MF4PRBEBGO2RTTBLQM6JY7HXJB","short_pith_number":"pith:MF4PRBEB","canonical_record":{"source":{"id":"1311.2400","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2013-11-11T10:07:56Z","cross_cats_sorted":[],"title_canon_sha256":"abeaaba6207bb2fbb97a9eacec24d5da20571e348710c2d5f08ece59f9eecdd1","abstract_canon_sha256":"ab72c52e8a5e12eded554e062fc7260d35d8a71786e9e7e7f6af3942fce4d6fd"},"schema_version":"1.0"},"canonical_sha256":"6178f8848133b519cc2b833c9c7cf7486da8a3f8ad69cd9106ca250c09654920","source":{"kind":"arxiv","id":"1311.2400","version":3},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.2400","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"arxiv_version","alias_value":"1311.2400v3","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.2400","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"pith_short_12","alias_value":"MF4PRBEBGO2R","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_16","alias_value":"MF4PRBEBGO2RTTBL","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_8","alias_value":"MF4PRBEB","created_at":"2026-05-18T12:27:52Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:MF4PRBEBGO2RTTBLQM6JY7HXJB","target":"record","payload":{"canonical_record":{"source":{"id":"1311.2400","kind":"arxiv","version":3},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2013-11-11T10:07:56Z","cross_cats_sorted":[],"title_canon_sha256":"abeaaba6207bb2fbb97a9eacec24d5da20571e348710c2d5f08ece59f9eecdd1","abstract_canon_sha256":"ab72c52e8a5e12eded554e062fc7260d35d8a71786e9e7e7f6af3942fce4d6fd"},"schema_version":"1.0"},"canonical_sha256":"6178f8848133b519cc2b833c9c7cf7486da8a3f8ad69cd9106ca250c09654920","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T01:25:24.820289Z","signature_b64":"kZb73wQuxvyMQo7RDxJoJXvzfLA2mVkUDz/80ZfMRwCw5AhXnn/bSJ9Jd65ERHd7wrc9oj69H8JAwOk442rLAw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"6178f8848133b519cc2b833c9c7cf7486da8a3f8ad69cd9106ca250c09654920","last_reissued_at":"2026-05-18T01:25:24.819799Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T01:25:24.819799Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1311.2400","source_version":3,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-18T01:25:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"dV2cyLUDN2KeyutKER3wOnbNvF7eKFWCLzs16w9iQly5e6rno7NHqqojIo87aaqn6Z88BFRm/krltFygYVQ9BA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-08T17:02:36.700484Z"},"content_sha256":"a285daa0a7b8870cb6c41c64e535e1edf8b7fecb2264c41059857b1971a5cf78","schema_version":"1.0","event_id":"sha256:a285daa0a7b8870cb6c41c64e535e1edf8b7fecb2264c41059857b1971a5cf78"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:MF4PRBEBGO2RTTBLQM6JY7HXJB","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Look-Ahead Removal for Top-Down Tree Transducers","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.FL","authors_text":"Helmut Seidl, Joost Engelfriet, Sebastian Maneth","submitted_at":"2013-11-11T10:07:56Z","abstract_excerpt":"Top-down tree transducers are a convenient formalism for describing tree transformations. They can be equipped with regular look-ahead, which allows them to inspect a subtree before processing it. In certain cases, such a look-ahead can be avoided and the transformation can be realized by a transducer without look-ahead. Removing the look-ahead from a transducer, if possible, is technically highly challenging. For a restricted class of transducers with look-ahead, namely those that are total, deterministic, ultralinear, and bounded erasing, we present an algorithm that, for a given transducer "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.2400","kind":"arxiv","version":3},"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":"2026-05-18T01:25:24Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MxeHjCLCB+iEkAZjxItMjdbMvHk1geXoy8pM+sb+O0oONgnJ79ucPhok/CLgT6LP9jhAhztFKHeqwKMLdlIDAA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-08T17:02:36.701089Z"},"content_sha256":"8638b2a1e969271db6003753e5c54e75bc7ceaaa4b54ff9f1fe90f85f60f6634","schema_version":"1.0","event_id":"sha256:8638b2a1e969271db6003753e5c54e75bc7ceaaa4b54ff9f1fe90f85f60f6634"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/bundle.json","state_url":"https://pith.science/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/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":"2026-06-08T17:02:36Z","links":{"resolver":"https://pith.science/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB","bundle":"https://pith.science/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/bundle.json","state":"https://pith.science/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/state.json","well_known_bundle":"https://pith.science/.well-known/pith/MF4PRBEBGO2RTTBLQM6JY7HXJB/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:MF4PRBEBGO2RTTBLQM6JY7HXJB","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":"ab72c52e8a5e12eded554e062fc7260d35d8a71786e9e7e7f6af3942fce4d6fd","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2013-11-11T10:07:56Z","title_canon_sha256":"abeaaba6207bb2fbb97a9eacec24d5da20571e348710c2d5f08ece59f9eecdd1"},"schema_version":"1.0","source":{"id":"1311.2400","kind":"arxiv","version":3}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1311.2400","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"arxiv_version","alias_value":"1311.2400v3","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1311.2400","created_at":"2026-05-18T01:25:24Z"},{"alias_kind":"pith_short_12","alias_value":"MF4PRBEBGO2R","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_16","alias_value":"MF4PRBEBGO2RTTBL","created_at":"2026-05-18T12:27:52Z"},{"alias_kind":"pith_short_8","alias_value":"MF4PRBEB","created_at":"2026-05-18T12:27:52Z"}],"graph_snapshots":[{"event_id":"sha256:8638b2a1e969271db6003753e5c54e75bc7ceaaa4b54ff9f1fe90f85f60f6634","target":"graph","created_at":"2026-05-18T01:25:24Z","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":"Top-down tree transducers are a convenient formalism for describing tree transformations. They can be equipped with regular look-ahead, which allows them to inspect a subtree before processing it. In certain cases, such a look-ahead can be avoided and the transformation can be realized by a transducer without look-ahead. Removing the look-ahead from a transducer, if possible, is technically highly challenging. For a restricted class of transducers with look-ahead, namely those that are total, deterministic, ultralinear, and bounded erasing, we present an algorithm that, for a given transducer ","authors_text":"Helmut Seidl, Joost Engelfriet, Sebastian Maneth","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2013-11-11T10:07:56Z","title":"Look-Ahead Removal for Top-Down Tree Transducers"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1311.2400","kind":"arxiv","version":3},"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:a285daa0a7b8870cb6c41c64e535e1edf8b7fecb2264c41059857b1971a5cf78","target":"record","created_at":"2026-05-18T01:25:24Z","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":"ab72c52e8a5e12eded554e062fc7260d35d8a71786e9e7e7f6af3942fce4d6fd","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2013-11-11T10:07:56Z","title_canon_sha256":"abeaaba6207bb2fbb97a9eacec24d5da20571e348710c2d5f08ece59f9eecdd1"},"schema_version":"1.0","source":{"id":"1311.2400","kind":"arxiv","version":3}},"canonical_sha256":"6178f8848133b519cc2b833c9c7cf7486da8a3f8ad69cd9106ca250c09654920","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"6178f8848133b519cc2b833c9c7cf7486da8a3f8ad69cd9106ca250c09654920","first_computed_at":"2026-05-18T01:25:24.819799Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T01:25:24.819799Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"kZb73wQuxvyMQo7RDxJoJXvzfLA2mVkUDz/80ZfMRwCw5AhXnn/bSJ9Jd65ERHd7wrc9oj69H8JAwOk442rLAw==","signature_status":"signed_v1","signed_at":"2026-05-18T01:25:24.820289Z","signed_message":"canonical_sha256_bytes"},"source_id":"1311.2400","source_kind":"arxiv","source_version":3}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:a285daa0a7b8870cb6c41c64e535e1edf8b7fecb2264c41059857b1971a5cf78","sha256:8638b2a1e969271db6003753e5c54e75bc7ceaaa4b54ff9f1fe90f85f60f6634"],"state_sha256":"8c0d580486b06ee1c576c2eec7a78e905be95b29a391287dd7279972e48dd61a"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"1vwZNsdsV6yB5DyT4Urm/uY0yZO+7w0jptg4y3FKOk6zAnW+rHKksBGmudlK4eZUPqaMiq/EsPoCzIGN5YMmDQ==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-08T17:02:36.704615Z","bundle_sha256":"dcea644ee792dc126a3afa9f19432902b47a881e867693fc1c2bcaa1b64a2676"}}