{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:DZ57E44LRMRKMDM3F5RVP7YEQA","short_pith_number":"pith:DZ57E44L","canonical_record":{"source":{"id":"1812.08948","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2018-12-21T05:02:48Z","cross_cats_sorted":[],"title_canon_sha256":"ea1d7212608ea699beab2e415793c43123c5e754c61992a74703c49d1c0ac4f6","abstract_canon_sha256":"86c19ac3ecc2c45712542c9d8f294aebe2c968adde08820e00a5dee0ba1ebfb6"},"schema_version":"1.0"},"canonical_sha256":"1e7bf2738b8b22a60d9b2f6357ff0480354a443bb2f99342549fddc011fd5878","source":{"kind":"arxiv","id":"1812.08948","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.08948","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"arxiv_version","alias_value":"1812.08948v1","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.08948","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"pith_short_12","alias_value":"DZ57E44LRMRK","created_at":"2026-05-18T12:32:19Z"},{"alias_kind":"pith_short_16","alias_value":"DZ57E44LRMRKMDM3","created_at":"2026-05-18T12:32:19Z"},{"alias_kind":"pith_short_8","alias_value":"DZ57E44L","created_at":"2026-05-18T12:32:19Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:DZ57E44LRMRKMDM3F5RVP7YEQA","target":"record","payload":{"canonical_record":{"source":{"id":"1812.08948","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2018-12-21T05:02:48Z","cross_cats_sorted":[],"title_canon_sha256":"ea1d7212608ea699beab2e415793c43123c5e754c61992a74703c49d1c0ac4f6","abstract_canon_sha256":"86c19ac3ecc2c45712542c9d8f294aebe2c968adde08820e00a5dee0ba1ebfb6"},"schema_version":"1.0"},"canonical_sha256":"1e7bf2738b8b22a60d9b2f6357ff0480354a443bb2f99342549fddc011fd5878","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-17T23:57:45.810635Z","signature_b64":"lriyx/57sLWaW+Xar5iWHSdix1p9HkeYcsZgones60iMi/FuOaZhOjbCzfXxQjUK3f2dS1YfAPXeO32wgkVUCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"1e7bf2738b8b22a60d9b2f6357ff0480354a443bb2f99342549fddc011fd5878","last_reissued_at":"2026-05-17T23:57:45.810121Z","signature_status":"signed_v1","first_computed_at":"2026-05-17T23:57:45.810121Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1812.08948","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":"2026-05-17T23:57:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"BDO/Xs8VGfIhQsfu77mdmr49MuyD8R7O/mku50+30P9i+DhPNJAbz13rxKHo4Ok4IjgvUyhS9aCjeFsiIForAQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T03:10:07.131962Z"},"content_sha256":"cce0a2e90cc146fa1a32d0b62f5bc6d22eea12f4750c6228c5f0f87ab7c4d927","schema_version":"1.0","event_id":"sha256:cce0a2e90cc146fa1a32d0b62f5bc6d22eea12f4750c6228c5f0f87ab7c4d927"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:DZ57E44LRMRKMDM3F5RVP7YEQA","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"The language preservation problem is undecidable for parametric event-recording automata","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":[],"primary_cat":"cs.FL","authors_text":"\\'Etienne Andr\\'e, Shang-Wei Lin","submitted_at":"2018-12-21T05:02:48Z","abstract_excerpt":"Parametric timed automata (PTA) extend timed automata with unknown constants (\"parameters\"), at the price of undecidability of most interesting problems. The (untimed) language preservation problem (\"given a parameter valuation, can we find at least one other valuation with the same untimed language?\") is undecidable for PTAs. We prove that this problem remains undecidable for parametric event-recording automata (PERAs), a subclass of PTAs that considerably restrains the way the language can be used; we also show it remains undecidable even for slightly different definitions of the language, i"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.08948","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":"2026-05-17T23:57:45Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"QikOr4IuF5xfu75eFuDuAOfPQrF5iURZM3PWd+k7oE91m76fTyLuMdelOidHoMZ1wxi5wZ2G38Nl8l3gFkhvAw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-06-05T03:10:07.132525Z"},"content_sha256":"25453c45419c8c59fbade23556e58028279f26a9e84ce4d369c74ac2dae22a2d","schema_version":"1.0","event_id":"sha256:25453c45419c8c59fbade23556e58028279f26a9e84ce4d369c74ac2dae22a2d"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/bundle.json","state_url":"https://pith.science/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/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":"2026-06-05T03:10:07Z","links":{"resolver":"https://pith.science/pith/DZ57E44LRMRKMDM3F5RVP7YEQA","bundle":"https://pith.science/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/bundle.json","state":"https://pith.science/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/state.json","well_known_bundle":"https://pith.science/.well-known/pith/DZ57E44LRMRKMDM3F5RVP7YEQA/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:DZ57E44LRMRKMDM3F5RVP7YEQA","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":"86c19ac3ecc2c45712542c9d8f294aebe2c968adde08820e00a5dee0ba1ebfb6","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2018-12-21T05:02:48Z","title_canon_sha256":"ea1d7212608ea699beab2e415793c43123c5e754c61992a74703c49d1c0ac4f6"},"schema_version":"1.0","source":{"id":"1812.08948","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1812.08948","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"arxiv_version","alias_value":"1812.08948v1","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1812.08948","created_at":"2026-05-17T23:57:45Z"},{"alias_kind":"pith_short_12","alias_value":"DZ57E44LRMRK","created_at":"2026-05-18T12:32:19Z"},{"alias_kind":"pith_short_16","alias_value":"DZ57E44LRMRKMDM3","created_at":"2026-05-18T12:32:19Z"},{"alias_kind":"pith_short_8","alias_value":"DZ57E44L","created_at":"2026-05-18T12:32:19Z"}],"graph_snapshots":[{"event_id":"sha256:25453c45419c8c59fbade23556e58028279f26a9e84ce4d369c74ac2dae22a2d","target":"graph","created_at":"2026-05-17T23:57:45Z","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":"Parametric timed automata (PTA) extend timed automata with unknown constants (\"parameters\"), at the price of undecidability of most interesting problems. The (untimed) language preservation problem (\"given a parameter valuation, can we find at least one other valuation with the same untimed language?\") is undecidable for PTAs. We prove that this problem remains undecidable for parametric event-recording automata (PERAs), a subclass of PTAs that considerably restrains the way the language can be used; we also show it remains undecidable even for slightly different definitions of the language, i","authors_text":"\\'Etienne Andr\\'e, Shang-Wei Lin","cross_cats":[],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2018-12-21T05:02:48Z","title":"The language preservation problem is undecidable for parametric event-recording automata"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1812.08948","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:cce0a2e90cc146fa1a32d0b62f5bc6d22eea12f4750c6228c5f0f87ab7c4d927","target":"record","created_at":"2026-05-17T23:57:45Z","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":"86c19ac3ecc2c45712542c9d8f294aebe2c968adde08820e00a5dee0ba1ebfb6","cross_cats_sorted":[],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.FL","submitted_at":"2018-12-21T05:02:48Z","title_canon_sha256":"ea1d7212608ea699beab2e415793c43123c5e754c61992a74703c49d1c0ac4f6"},"schema_version":"1.0","source":{"id":"1812.08948","kind":"arxiv","version":1}},"canonical_sha256":"1e7bf2738b8b22a60d9b2f6357ff0480354a443bb2f99342549fddc011fd5878","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"1e7bf2738b8b22a60d9b2f6357ff0480354a443bb2f99342549fddc011fd5878","first_computed_at":"2026-05-17T23:57:45.810121Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-17T23:57:45.810121Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"lriyx/57sLWaW+Xar5iWHSdix1p9HkeYcsZgones60iMi/FuOaZhOjbCzfXxQjUK3f2dS1YfAPXeO32wgkVUCQ==","signature_status":"signed_v1","signed_at":"2026-05-17T23:57:45.810635Z","signed_message":"canonical_sha256_bytes"},"source_id":"1812.08948","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:cce0a2e90cc146fa1a32d0b62f5bc6d22eea12f4750c6228c5f0f87ab7c4d927","sha256:25453c45419c8c59fbade23556e58028279f26a9e84ce4d369c74ac2dae22a2d"],"state_sha256":"2f8c9e53216715346d93cbf8ddd3614f0aa0cd47a79ab9d9f6ac0d9920339ec5"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"uAmPvYWH1CVDVIdMu7lF5orVBTqB1OJj/hrU6r6tUb1nEhweFbIGWwG9VVfwy1Nh9ejYw2H5CdgTdeNrk6fiCw==","signed_message":"bundle_sha256_bytes","signed_at":"2026-06-05T03:10:07.135891Z","bundle_sha256":"06e128122cbbb2aacc3068730ac99dd01d280dcb48cbd2fd49f9e0a5ed735b5a"}}