{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2018:Z6RP7AKTBHORG5NIPDSTIROXIF","short_pith_number":"pith:Z6RP7AKT","canonical_record":{"source":{"id":"1801.08339","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.DG","submitted_at":"2018-01-25T10:25:58Z","cross_cats_sorted":["nlin.SI"],"title_canon_sha256":"9fc81af2ad1c161a6bbc553775cc78e4426890e92c67b3d04a45ab1d8c820f59","abstract_canon_sha256":"ea8baf38a3ecee33148f4d792b76b6a0efea8502b46b15478eb4ea0b35ed32a7"},"schema_version":"1.0"},"canonical_sha256":"cfa2ff815309dd1375a878e53445d74143b04a6630858f427c2b1f05595553b4","source":{"kind":"arxiv","id":"1801.08339","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.08339","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"arxiv_version","alias_value":"1801.08339v1","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.08339","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"pith_short_12","alias_value":"Z6RP7AKTBHOR","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_16","alias_value":"Z6RP7AKTBHORG5NI","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_8","alias_value":"Z6RP7AKT","created_at":"2026-05-18T12:33:04Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2018:Z6RP7AKTBHORG5NIPDSTIROXIF","target":"record","payload":{"canonical_record":{"source":{"id":"1801.08339","kind":"arxiv","version":1},"metadata":{"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.DG","submitted_at":"2018-01-25T10:25:58Z","cross_cats_sorted":["nlin.SI"],"title_canon_sha256":"9fc81af2ad1c161a6bbc553775cc78e4426890e92c67b3d04a45ab1d8c820f59","abstract_canon_sha256":"ea8baf38a3ecee33148f4d792b76b6a0efea8502b46b15478eb4ea0b35ed32a7"},"schema_version":"1.0"},"canonical_sha256":"cfa2ff815309dd1375a878e53445d74143b04a6630858f427c2b1f05595553b4","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-05-18T00:11:38.726715Z","signature_b64":"EbXWc+hNMFzIl0rKNwN6TfW7rZyYdwccf6rZENhl5xvhbshSV96fdufpy9ueYm5sBuUZAg0/s8hYazAZiU9+Dw==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"cfa2ff815309dd1375a878e53445d74143b04a6630858f427c2b1f05595553b4","last_reissued_at":"2026-05-18T00:11:38.726095Z","signature_status":"signed_v1","first_computed_at":"2026-05-18T00:11:38.726095Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"1801.08339","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":"2026-05-18T00:11:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"+XXASwxwgiDz5jlBmDR6Jtu/ewSXsVWvLP2DfXz5zLb0HliUc9Af6+9nksVbcXAprn5uaxMf19UlSMzA2Y/uCQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T18:27:14.212950Z"},"content_sha256":"e877bab73431588b4a53373627cf72200033ffe530a060df75ca7370c5bf725b","schema_version":"1.0","event_id":"sha256:e877bab73431588b4a53373627cf72200033ffe530a060df75ca7370c5bf725b"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2018:Z6RP7AKTBHORG5NIPDSTIROXIF","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"Surface theory in discrete projective differential geometry. I. A canonical frame and an integrable discrete Demoulin system","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","headline":"","cross_cats":["nlin.SI"],"primary_cat":"math.DG","authors_text":"A. Szereszewski, W.K. Schief","submitted_at":"2018-01-25T10:25:58Z","abstract_excerpt":"We present the first steps of a procedure which discretises surface theory in classical projective differential geometry in such a manner that underlying integrable structure is preserved. We propose a canonical frame in terms of which the associated projective Gauss-Weingarten and Gauss-Mainardi-Codazzi equations adopt compact forms. Based on a scaling symmetry which injects a parameter into the linear Gauss-Weingarten equations, we set down an algebraic classification scheme of discrete projective minimal surfaces which turns out to admit a geometric counterpart formulated in terms of discre"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.08339","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":"2026-05-18T00:11:38Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"t21SQROOU015MkyjbGhTu8m6ql0e+lQdeVwA7JLln7GNxmyrwR6Rii+sA9qQ/IlWn8EtQzwFBYKbV6kmeJn5AQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-05-27T18:27:14.213378Z"},"content_sha256":"f799b80fbe3b259d47cadd5230c81abb6e561ee3b20ae99065058946d1607504","schema_version":"1.0","event_id":"sha256:f799b80fbe3b259d47cadd5230c81abb6e561ee3b20ae99065058946d1607504"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/bundle.json","state_url":"https://pith.science/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/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":"2026-05-27T18:27:14Z","links":{"resolver":"https://pith.science/pith/Z6RP7AKTBHORG5NIPDSTIROXIF","bundle":"https://pith.science/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/bundle.json","state":"https://pith.science/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/state.json","well_known_bundle":"https://pith.science/.well-known/pith/Z6RP7AKTBHORG5NIPDSTIROXIF/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2018:Z6RP7AKTBHORG5NIPDSTIROXIF","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":"ea8baf38a3ecee33148f4d792b76b6a0efea8502b46b15478eb4ea0b35ed32a7","cross_cats_sorted":["nlin.SI"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.DG","submitted_at":"2018-01-25T10:25:58Z","title_canon_sha256":"9fc81af2ad1c161a6bbc553775cc78e4426890e92c67b3d04a45ab1d8c820f59"},"schema_version":"1.0","source":{"id":"1801.08339","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"1801.08339","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"arxiv_version","alias_value":"1801.08339v1","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.1801.08339","created_at":"2026-05-18T00:11:38Z"},{"alias_kind":"pith_short_12","alias_value":"Z6RP7AKTBHOR","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_16","alias_value":"Z6RP7AKTBHORG5NI","created_at":"2026-05-18T12:33:04Z"},{"alias_kind":"pith_short_8","alias_value":"Z6RP7AKT","created_at":"2026-05-18T12:33:04Z"}],"graph_snapshots":[{"event_id":"sha256:f799b80fbe3b259d47cadd5230c81abb6e561ee3b20ae99065058946d1607504","target":"graph","created_at":"2026-05-18T00:11:38Z","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":"We present the first steps of a procedure which discretises surface theory in classical projective differential geometry in such a manner that underlying integrable structure is preserved. We propose a canonical frame in terms of which the associated projective Gauss-Weingarten and Gauss-Mainardi-Codazzi equations adopt compact forms. Based on a scaling symmetry which injects a parameter into the linear Gauss-Weingarten equations, we set down an algebraic classification scheme of discrete projective minimal surfaces which turns out to admit a geometric counterpart formulated in terms of discre","authors_text":"A. Szereszewski, W.K. Schief","cross_cats":["nlin.SI"],"headline":"","license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.DG","submitted_at":"2018-01-25T10:25:58Z","title":"Surface theory in discrete projective differential geometry. I. A canonical frame and an integrable discrete Demoulin system"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"1801.08339","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:e877bab73431588b4a53373627cf72200033ffe530a060df75ca7370c5bf725b","target":"record","created_at":"2026-05-18T00:11:38Z","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":"ea8baf38a3ecee33148f4d792b76b6a0efea8502b46b15478eb4ea0b35ed32a7","cross_cats_sorted":["nlin.SI"],"license":"http://arxiv.org/licenses/nonexclusive-distrib/1.0/","primary_cat":"math.DG","submitted_at":"2018-01-25T10:25:58Z","title_canon_sha256":"9fc81af2ad1c161a6bbc553775cc78e4426890e92c67b3d04a45ab1d8c820f59"},"schema_version":"1.0","source":{"id":"1801.08339","kind":"arxiv","version":1}},"canonical_sha256":"cfa2ff815309dd1375a878e53445d74143b04a6630858f427c2b1f05595553b4","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"cfa2ff815309dd1375a878e53445d74143b04a6630858f427c2b1f05595553b4","first_computed_at":"2026-05-18T00:11:38.726095Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-05-18T00:11:38.726095Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"EbXWc+hNMFzIl0rKNwN6TfW7rZyYdwccf6rZENhl5xvhbshSV96fdufpy9ueYm5sBuUZAg0/s8hYazAZiU9+Dw==","signature_status":"signed_v1","signed_at":"2026-05-18T00:11:38.726715Z","signed_message":"canonical_sha256_bytes"},"source_id":"1801.08339","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e877bab73431588b4a53373627cf72200033ffe530a060df75ca7370c5bf725b","sha256:f799b80fbe3b259d47cadd5230c81abb6e561ee3b20ae99065058946d1607504"],"state_sha256":"86195fa62c5953910da95c549261c6e9c6329336ae54d9336ae921a8b435083d"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"c98D2Ui6JOOpXyFSZVE1zawCuSLEYdlSj8AUR19zzT3xgdiiinaYBMXeUnDN1o4aB019tmVpC7JfLNTDB2PPAg==","signed_message":"bundle_sha256_bytes","signed_at":"2026-05-27T18:27:14.216786Z","bundle_sha256":"d60245d0909ca5040ffa73d7bbc6ad4ef1e64fcb31a4231111539bdb7ca869fa"}}