{"abstract":"A 12.5-cent special dividend leaves strikes unchanged.","category":"Options payoff and settlement","checks":8,"contract":"Inputs strike, contracts, deliverable, action and value. split [new, old]: if new is a multiple of old (ratio r), strike becomes strike/r rounded half-up to cents and contracts become contracts*r; otherwise the deliverable becomes floor(deliverable*new/old) with strike and contracts unchanged. special_div of at least 0.125 per share reduces the strike by the amount (rounded half-up to cents). Other actions, including ordinary_div, change nothing. Return [strike, contracts, deliverable].","contract_signature":"strike, contracts, deliverable, action, value","evaluation_group":"w2-options_payoff_and_settlement-corporate-action-adjustment","failed_approach":"Comparing mills against 12.5 adjusts nearly every dividend.","family":"w2-options_payoff_and_settlement-corporate-action-adjustment-special-dividend-threshold","id":"FA-61401","implementations":{"attempt":{"sha256":"86b2ca84090bba836c643af7e239b32ad9086c4c611be15c38aac0fa7fd615c1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(strike, contracts, deliverable, action, value):\n    k = round(strike * 100)\n    if action == 'split':\n        new, old = value\n        if new % old == 0:\n            r = new // old\n            k = (2 * k + r) // (2 * r)\n            contracts = contracts * r\n        else:\n            deliverable = deliverable * new // old\n    elif action == 'special_div':\n        amt = round(value * 1000)\n        if amt >= 12.5:\n            k = (k * 10 - amt + 5) // 10\n    return [k / 100, contracts, deliverable]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression special dividend threshold 1', [101.01, 10, 100, 'special_div', 0.125], [100.89, 10, 100]], ['regression special dividend threshold 2', [12.5, 3, 150, 'special_div', 0.125], [12.38, 3, 150]], ['partial repair probe 1', [150.05, 3, 100, 'special_div', 0.1], [150.05, 3, 100]], ['partial repair probe 2', [150.05, 10, 100, 'special_div', 0.124], [150.05, 10, 100]], ['boundary control 1', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [12.5, 3, 150, 'special_div', 0.01], [12.5, 3, 150]], ['normal control 2', [150.05, 1, 150, 'ordinary_div', 2.375], [150.05, 1, 150]]], [['regression special dividend threshold 1', [87.75, 1, 150, 'special_div', 0.125], [87.63, 1, 150]], ['regression special dividend threshold 2', [40, 1, 150, 'special_div', 0.125], [39.88, 1, 150]], ['partial repair probe 1', [87.75, 3, 100, 'special_div', 0.1], [87.75, 3, 100]], ['partial repair probe 2', [150.05, 1, 100, 'special_div', 0.124], [150.05, 1, 100]], ['boundary control 1', [40, 1, 100, 'ordinary_div', 1.0], [40.0, 1, 100]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [12.5, 3, 100, 'merger', 0.5], [12.5, 3, 100]], ['normal control 2', [87.75, 3, 150, 'split', [3, 1]], [29.25, 9, 150]]], [['regression special dividend threshold 1', [87.75, 10, 100, 'special_div', 0.125], [87.63, 10, 100]], ['regression special dividend threshold 2', [33.33, 1, 100, 'special_div', 0.125], [33.21, 1, 100]], ['partial repair probe 1', [101.01, 10, 150, 'special_div', 0.1], [101.01, 10, 150]], ['partial repair probe 2', [150.05, 1, 150, 'special_div', 0.124], [150.05, 1, 150]], ['boundary control 1', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['boundary control 2', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['normal control 1', [87.75, 3, 100, 'split', [5, 4]], [87.75, 3, 125]], ['normal control 2', [12.5, 1, 100, 'split', [1, 2]], [12.5, 1, 50]]], [['regression special dividend threshold 1', [40, 1, 100, 'special_div', 0.125], [39.88, 1, 100]], ['regression special dividend threshold 2', [12.5, 10, 100, 'special_div', 0.125], [12.38, 10, 100]], ['partial repair probe 1', [25.25, 1, 150, 'special_div', 0.1], [25.25, 1, 150]], ['partial repair probe 2', [33.33, 1, 150, 'special_div', 0.124], [33.33, 1, 150]], ['boundary control 1', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['boundary control 2', [40, 1, 100, 'ordinary_div', 1.0], [40.0, 1, 100]], ['normal control 1', [25.25, 3, 100, 'ordinary_div', 0.5], [25.25, 3, 100]], ['normal control 2', [47.5, 10, 100, 'merger', 0.5], [47.5, 10, 100]]], [['regression special dividend threshold 1', [12.5, 1, 100, 'special_div', 0.125], [12.38, 1, 100]], ['regression special dividend threshold 2', [40, 3, 150, 'special_div', 0.125], [39.88, 3, 150]], ['partial repair probe 1', [25.25, 10, 150, 'special_div', 0.124], [25.25, 10, 150]], ['partial repair probe 2', [101.01, 1, 100, 'special_div', 0.1], [101.01, 1, 100]], ['boundary control 1', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [87.75, 3, 100, 'merger', 0.124], [87.75, 3, 100]], ['normal control 2', [25.25, 10, 150, 'special_div', 1.25], [24.0, 10, 150]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"987971ef4fe972f6a77a20927eeb243e07b607258ac570ffb9b47d8a4cb694d1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(strike, contracts, deliverable, action, value):\n    k = round(strike * 100)\n    if action == 'split':\n        new, old = value\n        if new % old == 0:\n            r = new // old\n            k = (2 * k + r) // (2 * r)\n            contracts = contracts * r\n        else:\n            deliverable = deliverable * new // old\n    elif action == 'special_div':\n        amt = round(value * 1000)\n        if amt > 125:\n            k = (k * 10 - amt + 5) // 10\n    return [k / 100, contracts, deliverable]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['regression special dividend threshold 1', [101.01, 10, 100, 'special_div', 0.125], [100.89, 10, 100]], ['regression special dividend threshold 2', [12.5, 3, 150, 'special_div', 0.125], [12.38, 3, 150]], ['partial repair probe 1', [150.05, 3, 100, 'special_div', 0.1], [150.05, 3, 100]], ['partial repair probe 2', [150.05, 10, 100, 'special_div', 0.124], [150.05, 10, 100]], ['boundary control 1', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [12.5, 3, 150, 'special_div', 0.01], [12.5, 3, 150]], ['normal control 2', [150.05, 1, 150, 'ordinary_div', 2.375], [150.05, 1, 150]]], [['regression special dividend threshold 1', [87.75, 1, 150, 'special_div', 0.125], [87.63, 1, 150]], ['regression special dividend threshold 2', [40, 1, 150, 'special_div', 0.125], [39.88, 1, 150]], ['partial repair probe 1', [87.75, 3, 100, 'special_div', 0.1], [87.75, 3, 100]], ['partial repair probe 2', [150.05, 1, 100, 'special_div', 0.124], [150.05, 1, 100]], ['boundary control 1', [40, 1, 100, 'ordinary_div', 1.0], [40.0, 1, 100]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [12.5, 3, 100, 'merger', 0.5], [12.5, 3, 100]], ['normal control 2', [87.75, 3, 150, 'split', [3, 1]], [29.25, 9, 150]]], [['regression special dividend threshold 1', [87.75, 10, 100, 'special_div', 0.125], [87.63, 10, 100]], ['regression special dividend threshold 2', [33.33, 1, 100, 'special_div', 0.125], [33.21, 1, 100]], ['partial repair probe 1', [101.01, 10, 150, 'special_div', 0.1], [101.01, 10, 150]], ['partial repair probe 2', [150.05, 1, 150, 'special_div', 0.124], [150.05, 1, 150]], ['boundary control 1', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['boundary control 2', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['normal control 1', [87.75, 3, 100, 'split', [5, 4]], [87.75, 3, 125]], ['normal control 2', [12.5, 1, 100, 'split', [1, 2]], [12.5, 1, 50]]], [['regression special dividend threshold 1', [40, 1, 100, 'special_div', 0.125], [39.88, 1, 100]], ['regression special dividend threshold 2', [12.5, 10, 100, 'special_div', 0.125], [12.38, 10, 100]], ['partial repair probe 1', [25.25, 1, 150, 'special_div', 0.1], [25.25, 1, 150]], ['partial repair probe 2', [33.33, 1, 150, 'special_div', 0.124], [33.33, 1, 150]], ['boundary control 1', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['boundary control 2', [40, 1, 100, 'ordinary_div', 1.0], [40.0, 1, 100]], ['normal control 1', [25.25, 3, 100, 'ordinary_div', 0.5], [25.25, 3, 100]], ['normal control 2', [47.5, 10, 100, 'merger', 0.5], [47.5, 10, 100]]], [['regression special dividend threshold 1', [12.5, 1, 100, 'special_div', 0.125], [12.38, 1, 100]], ['regression special dividend threshold 2', [40, 3, 150, 'special_div', 0.125], [39.88, 3, 150]], ['partial repair probe 1', [25.25, 10, 150, 'special_div', 0.124], [25.25, 10, 150]], ['partial repair probe 2', [101.01, 1, 100, 'special_div', 0.1], [101.01, 1, 100]], ['boundary control 1', [40, 1, 100, 'split', [3, 2]], [40.0, 1, 150]], ['boundary control 2', [25.25, 1, 100, 'split', [2, 1]], [12.63, 2, 100]], ['normal control 1', [87.75, 3, 100, 'merger', 0.124], [87.75, 3, 100]], ['normal control 2', [25.25, 10, 150, 'special_div', 1.25], [24.0, 10, 150]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic toy contract stated explicitly in the contract field; no claim of conformance to any exchange or clearing rulebook. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-options_payoff_and_settlement-corporate-action-adjustment-special-dividend-threshold","generated_at":"2026-09-29T14:46:54.862222+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Option expiry, exercise and settlement engines move cash and shares; a wrong branch misstates obligations.","root_cause":"The threshold comparison is strict.","sha256":"3e0322c0130428c802163f61193052fac045c42645bc6496bf02a1944d36ab27","title":"Contract adjustment for splits and special dividends: a dividend exactly at the threshold is not adjusted · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":42.027,"exit_code":1,"observations":[{"actual":[100.89,10,100],"check":"regression special dividend threshold 1","expected":[100.89,10,100],"passed":true},{"actual":[12.38,3,150],"check":"regression special dividend threshold 2","expected":[12.38,3,150],"passed":true},{"actual":[149.95,3,100],"check":"partial repair probe 1","expected":[150.05,3,100],"passed":false},{"actual":[149.93,10,100],"check":"partial repair probe 2","expected":[150.05,10,100],"passed":false},{"actual":[40.0,1,150],"check":"boundary control 1","expected":[40.0,1,150],"passed":true},{"actual":[12.63,2,100],"check":"boundary control 2","expected":[12.63,2,100],"passed":true},{"actual":[12.5,3,150],"check":"normal control 1","expected":[12.5,3,150],"passed":true},{"actual":[150.05,1,150],"check":"normal control 2","expected":[150.05,1,150],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression special dividend threshold 1\", \"actual\": [100.89, 10, 100], \"expected\": [100.89, 10, 100], \"passed\": true}, {\"check\": \"regression special dividend threshold 2\", \"actual\": [12.38, 3, 150], \"expected\": [12.38, 3, 150], \"passed\": true}, {\"check\": \"partial repair probe 1\", \"actual\": [149.95, 3, 100], \"expected\": [150.05, 3, 100], \"passed\": false}, {\"check\": \"partial repair probe 2\", \"actual\": [149.93, 10, 100], \"expected\": [150.05, 10, 100], \"passed\": false}, {\"check\": \"boundary control 1\", \"actual\": [40.0, 1, 150], \"expected\": [40.0, 1, 150], \"passed\": true}, {\"check\": \"boundary control 2\", \"actual\": [12.63, 2, 100], \"expected\": [12.63, 2, 100], \"passed\": true}, {\"check\": \"normal control 1\", \"actual\": [12.5, 3, 150], \"expected\": [12.5, 3, 150], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [150.05, 1, 150], \"expected\": [150.05, 1, 150], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.333,"exit_code":1,"observations":[{"actual":[101.01,10,100],"check":"regression special dividend threshold 1","expected":[100.89,10,100],"passed":false},{"actual":[12.5,3,150],"check":"regression special dividend threshold 2","expected":[12.38,3,150],"passed":false},{"actual":[150.05,3,100],"check":"partial repair probe 1","expected":[150.05,3,100],"passed":true},{"actual":[150.05,10,100],"check":"partial repair probe 2","expected":[150.05,10,100],"passed":true},{"actual":[40.0,1,150],"check":"boundary control 1","expected":[40.0,1,150],"passed":true},{"actual":[12.63,2,100],"check":"boundary control 2","expected":[12.63,2,100],"passed":true},{"actual":[12.5,3,150],"check":"normal control 1","expected":[12.5,3,150],"passed":true},{"actual":[150.05,1,150],"check":"normal control 2","expected":[150.05,1,150],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression special dividend threshold 1\", \"actual\": [101.01, 10, 100], \"expected\": [100.89, 10, 100], \"passed\": false}, {\"check\": \"regression special dividend threshold 2\", \"actual\": [12.5, 3, 150], \"expected\": [12.38, 3, 150], \"passed\": false}, {\"check\": \"partial repair probe 1\", \"actual\": [150.05, 3, 100], \"expected\": [150.05, 3, 100], \"passed\": true}, {\"check\": \"partial repair probe 2\", \"actual\": [150.05, 10, 100], \"expected\": [150.05, 10, 100], \"passed\": true}, {\"check\": \"boundary control 1\", \"actual\": [40.0, 1, 150], \"expected\": [40.0, 1, 150], \"passed\": true}, {\"check\": \"boundary control 2\", \"actual\": [12.63, 2, 100], \"expected\": [12.63, 2, 100], \"passed\": true}, {\"check\": \"normal control 1\", \"actual\": [12.5, 3, 150], \"expected\": [12.5, 3, 150], \"passed\": true}, {\"check\": \"normal control 2\", \"actual\": [150.05, 1, 150], \"expected\": [150.05, 1, 150], \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}