{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2013:T377UTBVLGHUFUV6ROWYZ2M6HD","short_pith_number":"pith:T377UTBV","canonical_record":{"source":{"id":"1305.3102","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-05-14T10:43:00Z","cross_cats_sorted":["cs.DS"],"title_canon_sha256":"92f51e973831d8d68e1c5807561a0b365680eb02a61ab1f5fd0a01af368f6724","abstract_canon_sha256":"c3bd4b042e32daf138d6a093e6fd9110937bc3b55b85e2869678d548c4cba9f4"},"schema_version":"1.0"},"canonical_sha256":"9efffa4c35598f42d2be8bad8ce99e38cbf2f9fbfd8036a98660b3ee7ede7fc7","source":{"kind":"arxiv","id":"1305.3102","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1305.3102","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"arxiv_version","alias_value":"1305.3102v1","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1305.3102","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"pith_short_12","alias_value":"T377UTBVLGHU","created_at":"2026-05-18T12:27:59Z"},{"alias_kind":"pith_short_16","alias_value":"T377UTBVLGHUFUV6","created_at":"2026-05-18T12:27:59Z"},{"alias_kind":"pith_short_8","alias_value":"T377UTBV","created_at":"2026-05-18T12:27:59Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2013:T377UTBVLGHUFUV6ROWYZ2M6HD","target":"record","payload":{"canonical_record":{"source":{"id":"1305.3102","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-05-14T10:43:00Z","cross_cats_sorted":["cs.DS"],"title_canon_sha256":"92f51e973831d8d68e1c5807561a0b365680eb02a61ab1f5fd0a01af368f6724","abstract_canon_sha256":"c3bd4b042e32daf138d6a093e6fd9110937bc3b55b85e2869678d548c4cba9f4"},"schema_version":"1.0"},"canonical_sha256":"9efffa4c35598f42d2be8bad8ce99e38cbf2f9fbfd8036a98660b3ee7ede7fc7","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:25:44.847797Z","signature_b64":"JbE9qOyHPq/bXXRImZNwmF207p5kA/C9Xt0m3aShIrKRZ5aQzauwci7PWkb9jHu0gigp0+v1sukl2WKsPA+KBA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"9efffa4c35598f42d2be8bad8ce99e38cbf2f9fbfd8036a98660b3ee7ede7fc7","last_reissued_at":"2026-05-18T03:25:44.847028Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:25:44.847028Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1305.3102","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":"2026-05-18T03:25:44Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"WnqyHpRwoc9+t4epry0UJ7MkinBgMis6C7tACuSmzILp9PM3vhyb/BviQHwbBSdkN+E/7b6cptZR6MB1UB1XCg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T17:09:40.822093Z"},"content_sha256":"0e3772e498ae06fd6b6e2d032b5ac3ab93611b1c68ea0586ea9905017928dd1e","schema_version":"1.0","event_id":"sha256:0e3772e498ae06fd6b6e2d032b5ac3ab93611b1c68ea0586ea9905017928dd1e"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2013:T377UTBVLGHUFUV6ROWYZ2M6HD","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"FPT is Characterized by Useful Obstruction Sets","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["cs.DS"],"primary_cat":"cs.CC","authors_text":"Bart M. P. Jansen, Michael R. Fellows","submitted_at":"2013-05-14T10:43:00Z","abstract_excerpt":"Many graph problems were first shown to be fixed-parameter tractable using the results of Robertson and Seymour on graph minors. We show that the combination of finite, computable, obstruction sets and efficient order tests is not just one way of obtaining strongly uniform FPT algorithms, but that all of FPT may be captured in this way. Our new characterization of FPT has a strong connection to the theory of kernelization, as we prove that problems with polynomial kernels can be characterized by obstruction sets whose elements have polynomial size. Consequently we investigate the interplay bet"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1305.3102","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":"2026-05-18T03:25:44Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"AzsEGXwPqm4+tZRTpM+k7pMfegYCqW+zASkQn7JeRDkQq58JgvJdj3xsRtCmbohWPgD5bzrm1gLnjqhwEzjXBg==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-26T17:09:40.822785Z"},"content_sha256":"b1fd054bca6a6eb775bc6932954a6b6556824b86116c27640a6d18029ee1fe46","schema_version":"1.0","event_id":"sha256:b1fd054bca6a6eb775bc6932954a6b6556824b86116c27640a6d18029ee1fe46"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/bundle.json","state_url":"https://pith.science/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/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":"2026-05-26T17:09:40Z","links":{"resolver":"https://pith.science/pith/T377UTBVLGHUFUV6ROWYZ2M6HD","bundle":"https://pith.science/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/bundle.json","state":"https://pith.science/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/state.json","well_known_bundle":"https://pith.science/.well-known/pith/T377UTBVLGHUFUV6ROWYZ2M6HD/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2013:T377UTBVLGHUFUV6ROWYZ2M6HD","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":"c3bd4b042e32daf138d6a093e6fd9110937bc3b55b85e2869678d548c4cba9f4","cross_cats_sorted":["cs.DS"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-05-14T10:43:00Z","title_canon_sha256":"92f51e973831d8d68e1c5807561a0b365680eb02a61ab1f5fd0a01af368f6724"},"schema_version":"1.0","source":{"id":"1305.3102","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1305.3102","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"arxiv_version","alias_value":"1305.3102v1","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1305.3102","created_at":"2026-05-18T03:25:44Z"},{"alias_kind":"pith_short_12","alias_value":"T377UTBVLGHU","created_at":"2026-05-18T12:27:59Z"},{"alias_kind":"pith_short_16","alias_value":"T377UTBVLGHUFUV6","created_at":"2026-05-18T12:27:59Z"},{"alias_kind":"pith_short_8","alias_value":"T377UTBV","created_at":"2026-05-18T12:27:59Z"}],"graph_snapshots":[{"event_id":"sha256:b1fd054bca6a6eb775bc6932954a6b6556824b86116c27640a6d18029ee1fe46","target":"graph","created_at":"2026-05-18T03:25:44Z","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":"Many graph problems were first shown to be fixed-parameter tractable using the results of Robertson and Seymour on graph minors. We show that the combination of finite, computable, obstruction sets and efficient order tests is not just one way of obtaining strongly uniform FPT algorithms, but that all of FPT may be captured in this way. Our new characterization of FPT has a strong connection to the theory of kernelization, as we prove that problems with polynomial kernels can be characterized by obstruction sets whose elements have polynomial size. Consequently we investigate the interplay bet","authors_text":"Bart M. P. Jansen, Michael R. Fellows","cross_cats":["cs.DS"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-05-14T10:43:00Z","title":"FPT is Characterized by Useful Obstruction Sets"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1305.3102","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":"sha256:0e3772e498ae06fd6b6e2d032b5ac3ab93611b1c68ea0586ea9905017928dd1e","target":"record","created_at":"2026-05-18T03:25:44Z","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":"c3bd4b042e32daf138d6a093e6fd9110937bc3b55b85e2869678d548c4cba9f4","cross_cats_sorted":["cs.DS"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"cs.CC","submitted_at":"2013-05-14T10:43:00Z","title_canon_sha256":"92f51e973831d8d68e1c5807561a0b365680eb02a61ab1f5fd0a01af368f6724"},"schema_version":"1.0","source":{"id":"1305.3102","kind":"arxiv","version":1}},"canonical_sha256":"9efffa4c35598f42d2be8bad8ce99e38cbf2f9fbfd8036a98660b3ee7ede7fc7","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"9efffa4c35598f42d2be8bad8ce99e38cbf2f9fbfd8036a98660b3ee7ede7fc7","first_computed_at":"2026-05-18T03:25:44.847028Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T03:25:44.847028Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"JbE9qOyHPq/bXXRImZNwmF207p5kA/C9Xt0m3aShIrKRZ5aQzauwci7PWkb9jHu0gigp0+v1sukl2WKsPA+KBA==","signature_status":"signed_v1","signed_at":"2026-05-18T03:25:44.847797Z","signed_message":"canonical_sha256_bytes"},"source_id":"1305.3102","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:0e3772e498ae06fd6b6e2d032b5ac3ab93611b1c68ea0586ea9905017928dd1e","sha256:b1fd054bca6a6eb775bc6932954a6b6556824b86116c27640a6d18029ee1fe46"],"state_sha256":"eaf2709553135ca7eefcc443c37aac94da2085db7cf874f944076bc4779e32ff"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"lNdjtN7qClWSSmCmX+2ZnISwjexMHG2RJpZLuNycvrZG3qYyiJbR0dnfLIbsocL4qomSO8pM+J93xRKlyKPYDA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-26T17:09:40.825918Z","bundle_sha256":"2cd8cd2c951c17ba19187b8d858ef63f6c558393e81e5e97a7da343c22ac7bab"}}