{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2016:UQ2E5FA66BH7SSVQVN2OUULIS3","short_pith_number":"pith:UQ2E5FA6","canonical_record":{"source":{"id":"1607.04180","kind":"arxiv","version":5},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2016-07-14T16:07:29Z","cross_cats_sorted":[],"title_canon_sha256":"8194db7c020d4ba0d6fa0fdeb16cf178a9f442d505311ec08b485bfc02242234","abstract_canon_sha256":"d4ac05aed1f6ac30dcfb759a98b978d5125eeff32364258d23b20a8f50e0e554"},"schema_version":"1.0"},"canonical_sha256":"a4344e941ef04ff94ab0ab74ea516896e1bd6dbc41b020ee159741bdc1047017","source":{"kind":"arxiv","id":"1607.04180","version":5},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1607.04180","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"arxiv_version","alias_value":"1607.04180v5","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1607.04180","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"pith_short_12","alias_value":"UQ2E5FA66BH7","created_at":"2026-05-18T12:30:46Z"},{"alias_kind":"pith_short_16","alias_value":"UQ2E5FA66BH7SSVQ","created_at":"2026-05-18T12:30:46Z"},{"alias_kind":"pith_short_8","alias_value":"UQ2E5FA6","created_at":"2026-05-18T12:30:46Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2016:UQ2E5FA66BH7SSVQVN2OUULIS3","target":"record","payload":{"canonical_record":{"source":{"id":"1607.04180","kind":"arxiv","version":5},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2016-07-14T16:07:29Z","cross_cats_sorted":[],"title_canon_sha256":"8194db7c020d4ba0d6fa0fdeb16cf178a9f442d505311ec08b485bfc02242234","abstract_canon_sha256":"d4ac05aed1f6ac30dcfb759a98b978d5125eeff32364258d23b20a8f50e0e554"},"schema_version":"1.0"},"canonical_sha256":"a4344e941ef04ff94ab0ab74ea516896e1bd6dbc41b020ee159741bdc1047017","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:54:57.058053Z","signature_b64":"PQpFvCt6hDsExO9Fnvjf5b3wV6/LfgwPqJBpZcvM75CI6DQ5aQfMt9nlIbebYyrZui5RoF9upyvfI/gljp4WDw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"a4344e941ef04ff94ab0ab74ea516896e1bd6dbc41b020ee159741bdc1047017","last_reissued_at":"2026-05-17T23:54:57.057435Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:54:57.057435Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1607.04180","source_version":5,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-05-17T23:54:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VmTzCGYv8CQw3cWLCRlrf5Xw9oi1kNP3egrHNOLZI0/N9KUapYgIMbjCh23yapKtR0p3y1TdfSpkb8AUTL7xAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T12:52:17.090827Z"},"content_sha256":"d0583fd6334614af7ddc4aaece3532241f93823f7ffbc8bbadab7a38439438f9","schema_version":"1.0","event_id":"sha256:d0583fd6334614af7ddc4aaece3532241f93823f7ffbc8bbadab7a38439438f9"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2016:UQ2E5FA66BH7SSVQVN2OUULIS3","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Hazelnut: A Bidirectionally Typed Structure Editor Calculus","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.PL","authors_text":"Cyrus Omar, Ian Voysey, Jonathan Aldrich, Matthew A. Hammer, Michael Hilton","submitted_at":"2016-07-14T16:07:29Z","abstract_excerpt":"Structure editors allow programmers to edit the tree structure of a program directly. This can have cognitive benefits, particularly for novice and end-user programmers. It also simplifies matters for tool designers, because they do not need to contend with malformed program text. This paper defines Hazelnut, a structure editor based on a small bidirectionally typed lambda calculus extended with holes and a cursor. Hazelnut goes one step beyond syntactic well-formedness: its edit actions operate over statically meaningful incomplete terms. Naively, this would force the programmer to construct "},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1607.04180","kind":"arxiv","version":5},"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":"2026-05-17T23:54:57Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"kPV1/OLnd1YThFzMNT142iWeqLZ0esOeKELfnVcM/mg6AuQ2lbzRV8dePPCTzTab+KqIPmhZp5D09xR/U6/EAg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-27T12:52:17.091163Z"},"content_sha256":"a190bd7c71fb4c4a5e34e764284535fef09c9330cd854176c762d0a64ede109f","schema_version":"1.0","event_id":"sha256:a190bd7c71fb4c4a5e34e764284535fef09c9330cd854176c762d0a64ede109f"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/bundle.json","state_url":"https://pith.science/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/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":"2026-06-27T12:52:17Z","links":{"resolver":"https://pith.science/pith/UQ2E5FA66BH7SSVQVN2OUULIS3","bundle":"https://pith.science/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/bundle.json","state":"https://pith.science/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/state.json","well_known_bundle":"https://pith.science/.well-known/pith/UQ2E5FA66BH7SSVQVN2OUULIS3/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2016:UQ2E5FA66BH7SSVQVN2OUULIS3","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":"d4ac05aed1f6ac30dcfb759a98b978d5125eeff32364258d23b20a8f50e0e554","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2016-07-14T16:07:29Z","title_canon_sha256":"8194db7c020d4ba0d6fa0fdeb16cf178a9f442d505311ec08b485bfc02242234"},"schema_version":"1.0","source":{"id":"1607.04180","kind":"arxiv","version":5}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1607.04180","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"arxiv_version","alias_value":"1607.04180v5","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1607.04180","created_at":"2026-05-17T23:54:57Z"},{"alias_kind":"pith_short_12","alias_value":"UQ2E5FA66BH7","created_at":"2026-05-18T12:30:46Z"},{"alias_kind":"pith_short_16","alias_value":"UQ2E5FA66BH7SSVQ","created_at":"2026-05-18T12:30:46Z"},{"alias_kind":"pith_short_8","alias_value":"UQ2E5FA6","created_at":"2026-05-18T12:30:46Z"}],"graph_snapshots":[{"event_id":"sha256:a190bd7c71fb4c4a5e34e764284535fef09c9330cd854176c762d0a64ede109f","target":"graph","created_at":"2026-05-17T23:54:57Z","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":"Structure editors allow programmers to edit the tree structure of a program directly. This can have cognitive benefits, particularly for novice and end-user programmers. It also simplifies matters for tool designers, because they do not need to contend with malformed program text. This paper defines Hazelnut, a structure editor based on a small bidirectionally typed lambda calculus extended with holes and a cursor. Hazelnut goes one step beyond syntactic well-formedness: its edit actions operate over statically meaningful incomplete terms. Naively, this would force the programmer to construct ","authors_text":"Cyrus Omar, Ian Voysey, Jonathan Aldrich, Matthew A. Hammer, Michael Hilton","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2016-07-14T16:07:29Z","title":"Hazelnut: A Bidirectionally Typed Structure Editor Calculus"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1607.04180","kind":"arxiv","version":5},"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:d0583fd6334614af7ddc4aaece3532241f93823f7ffbc8bbadab7a38439438f9","target":"record","created_at":"2026-05-17T23:54:57Z","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":"d4ac05aed1f6ac30dcfb759a98b978d5125eeff32364258d23b20a8f50e0e554","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2016-07-14T16:07:29Z","title_canon_sha256":"8194db7c020d4ba0d6fa0fdeb16cf178a9f442d505311ec08b485bfc02242234"},"schema_version":"1.0","source":{"id":"1607.04180","kind":"arxiv","version":5}},"canonical_sha256":"a4344e941ef04ff94ab0ab74ea516896e1bd6dbc41b020ee159741bdc1047017","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"a4344e941ef04ff94ab0ab74ea516896e1bd6dbc41b020ee159741bdc1047017","first_computed_at":"2026-05-17T23:54:57.057435Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:54:57.057435Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PQpFvCt6hDsExO9Fnvjf5b3wV6/LfgwPqJBpZcvM75CI6DQ5aQfMt9nlIbebYyrZui5RoF9upyvfI/gljp4WDw==","signature_status":"signed_v1","signed_at":"2026-05-17T23:54:57.058053Z","signed_message":"canonical_sha256_bytes"},"source_id":"1607.04180","source_kind":"arxiv","source_version":5}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:d0583fd6334614af7ddc4aaece3532241f93823f7ffbc8bbadab7a38439438f9","sha256:a190bd7c71fb4c4a5e34e764284535fef09c9330cd854176c762d0a64ede109f"],"state_sha256":"31be1688338973a3fa4bc62975862c29c5c72926ac7822004938e1995edc92fb"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"MB2D3hLWkQCvjCWe23afJQFonVrv69HuVwmaz/EUoHKAvxqrlKShjVSzpjh8nCmI5Xk34wu+NmNw+s7nnOjuAw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-27T12:52:17.093130Z","bundle_sha256":"d19c92e5c05800c24281dd6f823973b92579864a6fdaa235f7f84fe66aa5939a"}}