{"paper":{"title":"Defeasible Conditional Obligation in a Two-tiered Preference-based Semantics (Extended Version)","license":"http://creativecommons.org/licenses/by/4.0/","headline":"A two-tiered preference semantics with separate ideality and normality orderings models defeasible conditional obligations that withdraw with new conflicting information.","cross_cats":["cs.AI"],"primary_cat":"cs.LO","authors_text":"Xavier Parent","submitted_at":"2026-04-28T11:04:26Z","abstract_excerpt":"In response to a concern raised by Horty, this paper develops a two-tiered, preference-based semantic framework for modeling defeasible conditional obligations. The paper extends a Hansson-Lewis style preference semantics for dyadic deontic logic by incorporating a nonmonotonic reasoning mechanism that enables previously derived obligations to be withdrawn when new, potentially conflicting information comes in. The account is bi-preferential: two orderings--ideality and normality--on worlds are employed to address shortcomings in earlier approaches, with a separate ranking method for each. At "},"claims":{"count":4,"items":[{"kind":"strongest_claim","text":"The account is bi-preferential: two orderings--ideality and normality--on worlds are employed to address shortcomings in earlier approaches, with a separate ranking method for each.","source":"verdict.strongest_claim","status":"machine_extracted","claim_id":"C1","attestation":"unclaimed"},{"kind":"weakest_assumption","text":"That the incorporation of a nonmonotonic reasoning mechanism via the two separate orderings (ideality and normality) with their respective ranking methods correctly enables withdrawal of obligations upon new conflicting information without introducing inconsistencies.","source":"verdict.weakest_assumption","status":"machine_extracted","claim_id":"C2","attestation":"unclaimed"},{"kind":"one_line_summary","text":"A bi-preferential semantics with ideality and normality orderings models defeasible conditional obligations and connects to constrained input/output logic.","source":"verdict.one_line_summary","status":"machine_extracted","claim_id":"C3","attestation":"unclaimed"},{"kind":"headline","text":"A two-tiered preference semantics with separate ideality and normality orderings models defeasible conditional obligations that withdraw with new conflicting information.","source":"verdict.pith_extraction.headline","status":"machine_extracted","claim_id":"C4","attestation":"unclaimed"}],"snapshot_sha256":"6cd51301c024adf48a9508470cdc6cf1de8cc507547a7e233241929a987f954e"},"source":{"id":"2604.26977","kind":"arxiv","version":2},"verdict":{"id":"27c99d97-6c10-40bb-814a-abef20095520","model_set":{"reader":"grok-4.3"},"created_at":"2026-05-07T14:34:25.164541Z","strongest_claim":"The account is bi-preferential: two orderings--ideality and normality--on worlds are employed to address shortcomings in earlier approaches, with a separate ranking method for each.","one_line_summary":"A bi-preferential semantics with ideality and normality orderings models defeasible conditional obligations and connects to constrained input/output logic.","pipeline_version":"pith-pipeline@v0.9.0","weakest_assumption":"That the incorporation of a nonmonotonic reasoning mechanism via the two separate orderings (ideality and normality) with their respective ranking methods correctly enables withdrawal of obligations upon new conflicting information without introducing inconsistencies.","pith_extraction_headline":"A two-tiered preference semantics with separate ideality and normality orderings models defeasible conditional obligations that withdraw with new conflicting information."},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2604.26977/integrity.json","findings":[],"available":true,"detectors_run":[{"name":"ai_meta_artifact","ran_at":"2026-05-21T04:39:27.271911Z","status":"completed","version":"1.0.0","findings_count":0},{"name":"doi_compliance","ran_at":"2026-05-19T21:06:04.321438Z","status":"completed","version":"1.0.0","findings_count":0}],"snapshot_sha256":"f6f1ddc18aeaf11b74737271012fe702c4a4699dae809290dafba751086d5c40"},"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"}