{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:XEWD6Q2WPYDGBEVHSTDVNHMX6K","short_pith_number":"pith:XEWD6Q2W","canonical_record":{"source":{"id":"1907.11133","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2019-07-25T15:17:27Z","cross_cats_sorted":[],"title_canon_sha256":"6e4c272b3ed0f6926f36eef957d4936c628850b0283fd910823e437d3d56337d","abstract_canon_sha256":"450b3f25c93c31a1ef536e4cf9f1f23f56531d7d2980077f5abc2fa4bc851f55"},"schema_version":"1.0"},"canonical_sha256":"b92c3f43567e066092a794c7569d97f2a2933a914b8d6d86dc80f59eb3984968","source":{"kind":"arxiv","id":"1907.11133","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.11133","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"arxiv_version","alias_value":"1907.11133v1","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.11133","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"pith_short_12","alias_value":"XEWD6Q2WPYDG","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"XEWD6Q2WPYDGBEVH","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"XEWD6Q2W","created_at":"2026-05-18T12:33:33Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:XEWD6Q2WPYDGBEVHSTDVNHMX6K","target":"record","payload":{"canonical_record":{"source":{"id":"1907.11133","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2019-07-25T15:17:27Z","cross_cats_sorted":[],"title_canon_sha256":"6e4c272b3ed0f6926f36eef957d4936c628850b0283fd910823e437d3d56337d","abstract_canon_sha256":"450b3f25c93c31a1ef536e4cf9f1f23f56531d7d2980077f5abc2fa4bc851f55"},"schema_version":"1.0"},"canonical_sha256":"b92c3f43567e066092a794c7569d97f2a2933a914b8d6d86dc80f59eb3984968","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:39:33.179542Z","signature_b64":"PmK0yPVTkyWtjGTsaWBdJpodc3a1Zrj8+CYzjUA4DaycOKK62bkcg5U00YCeFGtSgzrBdUiMZBzLUeZ1RzNODg==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b92c3f43567e066092a794c7569d97f2a2933a914b8d6d86dc80f59eb3984968","last_reissued_at":"2026-05-17T23:39:33.178745Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:39:33.178745Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1907.11133","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":"2026-05-17T23:39:33Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"r31wnoYhK0tkGAedQKChUkB5b6jOTCQYwBc2Ohn8srOaPLrCBktHCEwR3yo+//EXPzjfv9CG8xNRHzet4i7xBQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T08:00:46.790933Z"},"content_sha256":"259d9f3a3519c2bab12600a06ab440aa75a8303e6f3385fd80e733483cc464cd","schema_version":"1.0","event_id":"sha256:259d9f3a3519c2bab12600a06ab440aa75a8303e6f3385fd80e733483cc464cd"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:XEWD6Q2WPYDGBEVHSTDVNHMX6K","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"An Introduction to Logical Relations","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.PL","authors_text":"Lau Skorstengaard","submitted_at":"2019-07-25T15:17:27Z","abstract_excerpt":"Logical relations (LR) have been around for many years, and today they are used in many formal results. However, it can be difficult to LR beginners to find a good place to start to learn. Papers often use highly specialized LRs that use the latest advances of the technique which makes it impossible to make a proper presentation within the page limit.\n  This note is a good starting point for beginners that want to learn about LRs. Almost no prerequisite knowledge is assumed, and the note starts from the very basics. The note covers the following: LRs for proving normalization and type safety o"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.11133","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":""},"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":"2026-05-17T23:39:33Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"35cf6ECAUHIjMwJ7Gli6qE6bFb3JZMKHmr0Zh2LxGON9wt4Ct2nMlWd5A4O2yyUVv8TnwRB1LdFPcAL/Z0uzBA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-03T08:00:46.791281Z"},"content_sha256":"f0d1bbe941c66d9202b60010a80d1131ca1ddcbf5525ec07fb7b496df4bce9a3","schema_version":"1.0","event_id":"sha256:f0d1bbe941c66d9202b60010a80d1131ca1ddcbf5525ec07fb7b496df4bce9a3"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/bundle.json","state_url":"https://pith.science/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/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":"2026-06-03T08:00:46Z","links":{"resolver":"https://pith.science/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K","bundle":"https://pith.science/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/bundle.json","state":"https://pith.science/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/state.json","well_known_bundle":"https://pith.science/.well-known/pith/XEWD6Q2WPYDGBEVHSTDVNHMX6K/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:XEWD6Q2WPYDGBEVHSTDVNHMX6K","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":"450b3f25c93c31a1ef536e4cf9f1f23f56531d7d2980077f5abc2fa4bc851f55","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2019-07-25T15:17:27Z","title_canon_sha256":"6e4c272b3ed0f6926f36eef957d4936c628850b0283fd910823e437d3d56337d"},"schema_version":"1.0","source":{"id":"1907.11133","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1907.11133","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"arxiv_version","alias_value":"1907.11133v1","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1907.11133","created_at":"2026-05-17T23:39:33Z"},{"alias_kind":"pith_short_12","alias_value":"XEWD6Q2WPYDG","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_16","alias_value":"XEWD6Q2WPYDGBEVH","created_at":"2026-05-18T12:33:33Z"},{"alias_kind":"pith_short_8","alias_value":"XEWD6Q2W","created_at":"2026-05-18T12:33:33Z"}],"graph_snapshots":[{"event_id":"sha256:f0d1bbe941c66d9202b60010a80d1131ca1ddcbf5525ec07fb7b496df4bce9a3","target":"graph","created_at":"2026-05-17T23:39:33Z","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":"Logical relations (LR) have been around for many years, and today they are used in many formal results. However, it can be difficult to LR beginners to find a good place to start to learn. Papers often use highly specialized LRs that use the latest advances of the technique which makes it impossible to make a proper presentation within the page limit.\n  This note is a good starting point for beginners that want to learn about LRs. Almost no prerequisite knowledge is assumed, and the note starts from the very basics. The note covers the following: LRs for proving normalization and type safety o","authors_text":"Lau Skorstengaard","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2019-07-25T15:17:27Z","title":"An Introduction to Logical Relations"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1907.11133","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":"sha256:259d9f3a3519c2bab12600a06ab440aa75a8303e6f3385fd80e733483cc464cd","target":"record","created_at":"2026-05-17T23:39:33Z","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":"450b3f25c93c31a1ef536e4cf9f1f23f56531d7d2980077f5abc2fa4bc851f55","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.PL","submitted_at":"2019-07-25T15:17:27Z","title_canon_sha256":"6e4c272b3ed0f6926f36eef957d4936c628850b0283fd910823e437d3d56337d"},"schema_version":"1.0","source":{"id":"1907.11133","kind":"arxiv","version":1}},"canonical_sha256":"b92c3f43567e066092a794c7569d97f2a2933a914b8d6d86dc80f59eb3984968","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"b92c3f43567e066092a794c7569d97f2a2933a914b8d6d86dc80f59eb3984968","first_computed_at":"2026-05-17T23:39:33.178745Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:39:33.178745Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"PmK0yPVTkyWtjGTsaWBdJpodc3a1Zrj8+CYzjUA4DaycOKK62bkcg5U00YCeFGtSgzrBdUiMZBzLUeZ1RzNODg==","signature_status":"signed_v1","signed_at":"2026-05-17T23:39:33.179542Z","signed_message":"canonical_sha256_bytes"},"source_id":"1907.11133","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:259d9f3a3519c2bab12600a06ab440aa75a8303e6f3385fd80e733483cc464cd","sha256:f0d1bbe941c66d9202b60010a80d1131ca1ddcbf5525ec07fb7b496df4bce9a3"],"state_sha256":"0a7d3a50c5ce5f5f3c63b93de064fcd2ee6232dd3ac23928dc5fce68b040458a"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LPgeAb6g7y/D0fwm66l4qOOaaUul3ebNziGaAJ1+8nVhEYok/N17ns9e/hhK/GGnviu33iyKfHMHQVpkpQ9vBA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-03T08:00:46.793434Z","bundle_sha256":"0e483887708ac97648d230eed966263bed9e399dd57ef18c89c39c336cc7aa0a"}}