{"record_type":"pith_number_record","schema_url":"https://pith.science/schemas/pith-number/v1.json","pith_number":"pith:2012:XGHRVYNFUIUVK2KG7N75F7PMYJ","short_pith_number":"pith:XGHRVYNF","schema_version":"1.0","canonical_sha256":"b98f1ae1a5a229556946fb7fd2fdecc2722b029a58ead523dc73ba09cff70f87","source":{"kind":"arxiv","id":"1207.0052","version":3},"attestation_state":"computed","paper":{"title":"The Complexity of Learning Principles and Parameters Grammars","license":"http://creativecommons.org/licenses/publicdomain/","headline":"","cross_cats":["cs.CL"],"primary_cat":"cs.FL","authors_text":"Jacob Andreas","submitted_at":"2012-06-30T06:36:04Z","abstract_excerpt":"We investigate models for learning the class of context-free and context-sensitive languages (CFLs and CSLs). We begin with a brief discussion of some early hardness results which show that unrestricted language learning is impossible, and unrestricted CFL learning is computationally infeasible; we then briefly survey the literature on algorithms for learning restricted subclasses of the CFLs. Finally, we introduce a new family of subclasses, the principled parametric context-free grammars (and a corresponding family of principled parametric context-sensitive grammars), which roughly model the"},"verification_status":{"content_addressed":true,"pith_receipt":true,"author_attested":false,"weak_author_claims":0,"strong_author_claims":0,"externally_anchored":false,"storage_verified":false,"citation_signatures":0,"replication_records":0,"graph_snapshot":true,"references_resolved":false,"formal_links_present":false},"canonical_record":{"source":{"id":"1207.0052","kind":"arxiv","version":3},"metadata":{"license":"http://creativecommons.org/licenses/publicdomain/","primary_cat":"cs.FL","submitted_at":"2012-06-30T06:36:04Z","cross_cats_sorted":["cs.CL"],"title_canon_sha256":"b7dd58cc0206dba66488c2d2d20f8ed3214e2a8c8220a09ed74ad60676198c34","abstract_canon_sha256":"38dabdd8d617856051fd658f0fa11f3c5251843f2474946be51809a349761f1b"},"schema_version":"1.0"},"receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T03:51:37.816568Z","signature_b64":"l0WC3C+p+HzU16l0BsUmmZ4/4437lY0r3Kel1mVTHcgq+0DTO2nMqOjxRXXIETyuWvpBvdWGUqWKbGaIH0xnAA==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"b98f1ae1a5a229556946fb7fd2fdecc2722b029a58ead523dc73ba09cff70f87","last_reissued_at":"2026-05-18T03:51:37.815785Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T03:51:37.815785Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"graph_snapshot":{"paper":{"title":"The Complexity of Learning Principles and Parameters Grammars","license":"http://creativecommons.org/licenses/publicdomain/","headline":"","cross_cats":["cs.CL"],"primary_cat":"cs.FL","authors_text":"Jacob Andreas","submitted_at":"2012-06-30T06:36:04Z","abstract_excerpt":"We investigate models for learning the class of context-free and context-sensitive languages (CFLs and CSLs). We begin with a brief discussion of some early hardness results which show that unrestricted language learning is impossible, and unrestricted CFL learning is computationally infeasible; we then briefly survey the literature on algorithms for learning restricted subclasses of the CFLs. Finally, we introduce a new family of subclasses, the principled parametric context-free grammars (and a corresponding family of principled parametric context-sensitive grammars), which roughly model the"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1207.0052","kind":"arxiv","version":3},"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"},"aliases":[{"alias_kind":"arxiv","alias_value":"1207.0052","created_at":"2026-05-18T03:51:37.815897+00:00"},{"alias_kind":"arxiv_version","alias_value":"1207.0052v3","created_at":"2026-05-18T03:51:37.815897+00:00"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1207.0052","created_at":"2026-05-18T03:51:37.815897+00:00"},{"alias_kind":"pith_short_12","alias_value":"XGHRVYNFUIUV","created_at":"2026-05-18T12:27:27.928770+00:00"},{"alias_kind":"pith_short_16","alias_value":"XGHRVYNFUIUVK2KG","created_at":"2026-05-18T12:27:27.928770+00:00"},{"alias_kind":"pith_short_8","alias_value":"XGHRVYNF","created_at":"2026-05-18T12:27:27.928770+00:00"}],"events":[],"event_summary":{},"paper_claims":[],"inbound_citations":{"count":0,"internal_anchor_count":0,"sample":[]},"formal_canon":{"evidence_count":0,"sample":[],"anchors":[]},"links":{"html":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ","json":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ.json","graph_json":"https://pith.science/api/pith-number/XGHRVYNFUIUVK2KG7N75F7PMYJ/graph.json","events_json":"https://pith.science/api/pith-number/XGHRVYNFUIUVK2KG7N75F7PMYJ/events.json","paper":"https://pith.science/paper/XGHRVYNF"},"agent_actions":{"view_html":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ","download_json":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ.json","view_paper":"https://pith.science/paper/XGHRVYNF","resolve_alias":"https://pith.science/api/pith-number/resolve?arxiv=1207.0052&json=true","fetch_graph":"https://pith.science/api/pith-number/XGHRVYNFUIUVK2KG7N75F7PMYJ/graph.json","fetch_events":"https://pith.science/api/pith-number/XGHRVYNFUIUVK2KG7N75F7PMYJ/events.json","actions":{"anchor_timestamp":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ/action/timestamp_anchor","attest_storage":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ/action/storage_attestation","attest_author":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ/action/author_attestation","sign_citation":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ/action/citation_signature","submit_replication":"https://pith.science/pith/XGHRVYNFUIUVK2KG7N75F7PMYJ/action/replication_record"}},"created_at":"2026-05-18T03:51:37.815897+00:00","updated_at":"2026-05-18T03:51:37.815897+00:00"}