{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2019:E2KP764UJNR37VC4ZGJG4OMILV","short_pith_number":"pith:E2KP764U","canonical_record":{"source":{"id":"1908.05966","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2019-08-16T13:31:59Z","cross_cats_sorted":["math.CO"],"title_canon_sha256":"caabe2a933df8faada178d4eaf14c8ea18f53497fc3196f7b4c6b5de0ad565d4","abstract_canon_sha256":"28b43e671628f1d075aa7e8cf2ab164a6a2793b77ccd16b5170a80fc781a771f"},"schema_version":"1.0"},"canonical_sha256":"2694fffb944b63bfd45cc9926e39885d433dda27ed4897d812fdf0ba19bf2cbe","source":{"kind":"arxiv","id":"1908.05966","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1908.05966","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"arxiv_version","alias_value":"1908.05966v1","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1908.05966","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_12","alias_value":"E2KP764UJNR3","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_16","alias_value":"E2KP764UJNR37VC4","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_8","alias_value":"E2KP764U","created_at":"2026-07-05T00:55:58Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2019:E2KP764UJNR37VC4ZGJG4OMILV","target":"record","payload":{"canonical_record":{"source":{"id":"1908.05966","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2019-08-16T13:31:59Z","cross_cats_sorted":["math.CO"],"title_canon_sha256":"caabe2a933df8faada178d4eaf14c8ea18f53497fc3196f7b4c6b5de0ad565d4","abstract_canon_sha256":"28b43e671628f1d075aa7e8cf2ab164a6a2793b77ccd16b5170a80fc781a771f"},"schema_version":"1.0"},"canonical_sha256":"2694fffb944b63bfd45cc9926e39885d433dda27ed4897d812fdf0ba19bf2cbe","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-07-05T00:55:58.475067Z","signature_b64":"Ghr1+vox/1kPbWltyjCMpSeO2U2Z2LMuOXeIpyH6/kp4xdeWPzmkO4LednCQBoRVU1QZJOlJlR3MhCo4v/mWAQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"2694fffb944b63bfd45cc9926e39885d433dda27ed4897d812fdf0ba19bf2cbe","last_reissued_at":"2026-07-05T00:55:58.474576Z","signature_status":"signed_v1","first_computed_at":"2026-07-05T00:55:58.474576Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1908.05966","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":"2026-07-05T00:55:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"rTV1TDPbOB48Z3Fjg43HlR4fjtkfsEduM/IokU/0kXGYthQUcvJqy2LhYey7qKSCJ/esgGcmeBjzofmtxXkEDA==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-16T03:42:50.943907Z"},"content_sha256":"c8242ed7de0f80ba4d301ccc35292b96ad153c0f57f3215636f8aa1b138a0f64","schema_version":"1.0","event_id":"sha256:c8242ed7de0f80ba4d301ccc35292b96ad153c0f57f3215636f8aa1b138a0f64"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2019:E2KP764UJNR37VC4ZGJG4OMILV","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"LaserTank is NP-complete","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["math.CO"],"primary_cat":"cs.CC","authors_text":"Per Alexandersson, Petter Restadh","submitted_at":"2019-08-16T13:31:59Z","abstract_excerpt":"We show that the classical game LaserTank is $\\mathrm{NP}$-complete, even when the tank movement is restricted to a single column and the only blocks appearing on the board are mirrors and solid blocks. We show this by reducing $3$-SAT instances to LaserTank puzzles."},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1908.05966","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":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/1908.05966/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":"2026-07-05T00:55:58Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"4hp5ZT4BbU/iFudNXuOOfYGc1G18x+E5B90f1Rg12cMf5ilkWRjbJPhSrQpAKv4Cd9fM3M5gOHuyeZ+l6fAjDw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-08-16T03:42:50.944571Z"},"content_sha256":"693de2ad187348d6213ac4072cb64475b20d5357678f634e3795ab96fa0e5d40","schema_version":"1.0","event_id":"sha256:693de2ad187348d6213ac4072cb64475b20d5357678f634e3795ab96fa0e5d40"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/E2KP764UJNR37VC4ZGJG4OMILV/bundle.json","state_url":"https://pith.science/pith/E2KP764UJNR37VC4ZGJG4OMILV/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/E2KP764UJNR37VC4ZGJG4OMILV/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":"2026-08-16T03:42:50Z","links":{"resolver":"https://pith.science/pith/E2KP764UJNR37VC4ZGJG4OMILV","bundle":"https://pith.science/pith/E2KP764UJNR37VC4ZGJG4OMILV/bundle.json","state":"https://pith.science/pith/E2KP764UJNR37VC4ZGJG4OMILV/state.json","well_known_bundle":"https://pith.science/.well-known/pith/E2KP764UJNR37VC4ZGJG4OMILV/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2019:E2KP764UJNR37VC4ZGJG4OMILV","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":"28b43e671628f1d075aa7e8cf2ab164a6a2793b77ccd16b5170a80fc781a771f","cross_cats_sorted":["math.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2019-08-16T13:31:59Z","title_canon_sha256":"caabe2a933df8faada178d4eaf14c8ea18f53497fc3196f7b4c6b5de0ad565d4"},"schema_version":"1.0","source":{"id":"1908.05966","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1908.05966","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"arxiv_version","alias_value":"1908.05966v1","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1908.05966","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_12","alias_value":"E2KP764UJNR3","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_16","alias_value":"E2KP764UJNR37VC4","created_at":"2026-07-05T00:55:58Z"},{"alias_kind":"pith_short_8","alias_value":"E2KP764U","created_at":"2026-07-05T00:55:58Z"}],"graph_snapshots":[{"event_id":"sha256:693de2ad187348d6213ac4072cb64475b20d5357678f634e3795ab96fa0e5d40","target":"graph","created_at":"2026-07-05T00:55:58Z","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/1908.05966/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"We show that the classical game LaserTank is $\\mathrm{NP}$-complete, even when the tank movement is restricted to a single column and the only blocks appearing on the board are mirrors and solid blocks. We show this by reducing $3$-SAT instances to LaserTank puzzles.","authors_text":"Per Alexandersson, Petter Restadh","cross_cats":["math.CO"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2019-08-16T13:31:59Z","title":"LaserTank is NP-complete"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1908.05966","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:c8242ed7de0f80ba4d301ccc35292b96ad153c0f57f3215636f8aa1b138a0f64","target":"record","created_at":"2026-07-05T00:55:58Z","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":"28b43e671628f1d075aa7e8cf2ab164a6a2793b77ccd16b5170a80fc781a771f","cross_cats_sorted":["math.CO"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2019-08-16T13:31:59Z","title_canon_sha256":"caabe2a933df8faada178d4eaf14c8ea18f53497fc3196f7b4c6b5de0ad565d4"},"schema_version":"1.0","source":{"id":"1908.05966","kind":"arxiv","version":1}},"canonical_sha256":"2694fffb944b63bfd45cc9926e39885d433dda27ed4897d812fdf0ba19bf2cbe","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"2694fffb944b63bfd45cc9926e39885d433dda27ed4897d812fdf0ba19bf2cbe","first_computed_at":"2026-07-05T00:55:58.474576Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-05T00:55:58.474576Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"Ghr1+vox/1kPbWltyjCMpSeO2U2Z2LMuOXeIpyH6/kp4xdeWPzmkO4LednCQBoRVU1QZJOlJlR3MhCo4v/mWAQ==","signature_status":"signed_v1","signed_at":"2026-07-05T00:55:58.475067Z","signed_message":"canonical_sha256_bytes"},"source_id":"1908.05966","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:c8242ed7de0f80ba4d301ccc35292b96ad153c0f57f3215636f8aa1b138a0f64","sha256:693de2ad187348d6213ac4072cb64475b20d5357678f634e3795ab96fa0e5d40"],"state_sha256":"b6085470e5ffe4f8eaef4e69d460644862f1775fed24701a9ac392a5cf29e829"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"bbArWopGXEMKnOoAa0NSt6ezH7X4XCowdQLCYBq91LSCbo28Kxckq31jW4md7uWxi4sfaamWbtbzdRHOAAQMCg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-08-16T03:42:50.948047Z","bundle_sha256":"59987b13ff7a17704a0f40aaab12ac66a17187b29d643042be65d39f1b70beea"}}