{"abstract":"Opening a second panel in multiple mode closes the first.","category":"Disclosure widgets","checks":8,"contract":"Discard removed panels; ignore invalid targets; expanded panels close only when collapsible; multiple mode unions and single mode replaces.","contract_signature":"panels, opened, target, multiple, collapsible","evaluation_group":"xi-accordion","failed_approach":"Removing the target never opens it.","family":"xi-accordion-multi-open","id":"FA-8096","implementations":{"attempt":{"sha256":"11ae8756f4d6168c460f671273f9381d876cb44ca061c00f9d8f175155ba3fc7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(panels, opened, target, multiple, collapsible):\n    valid = set(panels)\n    opened = set(opened) & valid\n    if target not in valid: return sorted(opened)\n    if target in opened:\n        if collapsible: opened.remove(target)\n    elif multiple: opened.discard(target)\n    else: opened = {target}\n    return sorted(opened)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('removed', solve(['a','b'], ['a','gone'], 'unknown', True, True), ['a'])\ncheck('unknown', solve(['a','b'], ['a'], 'unknown', True, True), ['a'])\ncheck('locked', solve(['a','b'], ['a'], 'a', False, False), ['a'])\ncheck('collapse', solve(['a','b'], ['a'], 'a', False, True), [])\ncheck('multiple', solve(['a','b'], ['a'], 'b', True, True), ['a', 'b'])\ncheck('single', solve(['a','b'], ['a'], 'b', False, True), ['b'])\ncheck('parameterized panels', solve(list(range(N+1)), [0], N, True, True), [0,N])\nfor repetition in range(N):\n    check('repeat single', solve(['a','b'], ['a'], 'b', False, True), ['b'])\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":"4413714cb9af475fba787dcca6d03c25e9b8c156a57d009932efb23a20c8e22c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(panels, opened, target, multiple, collapsible):\n    valid = set(panels)\n    opened = set(opened) & valid\n    if target not in valid: return sorted(opened)\n    if target in opened:\n        if collapsible: opened.remove(target)\n    elif multiple: opened = {target}\n    else: opened = {target}\n    return sorted(opened)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('removed', solve(['a','b'], ['a','gone'], 'unknown', True, True), ['a'])\ncheck('unknown', solve(['a','b'], ['a'], 'unknown', True, True), ['a'])\ncheck('locked', solve(['a','b'], ['a'], 'a', False, False), ['a'])\ncheck('collapse', solve(['a','b'], ['a'], 'a', False, True), [])\ncheck('multiple', solve(['a','b'], ['a'], 'b', True, True), ['a', 'b'])\ncheck('single', solve(['a','b'], ['a'], 'b', False, True), ['b'])\ncheck('parameterized panels', solve(list(range(N+1)), [0], N, True, True), [0,N])\nfor repetition in range(N):\n    check('repeat single', solve(['a','b'], ['a'], 'b', False, True), ['b'])\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":" 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":"xi-accordion-multi-open","generated_at":"2026-09-29T14:38:18.132215+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic model of accordion open-panel state; this isolates one interface invariant without requiring a browser.","root_cause":"The multi open operation uses `elif multiple: opened = {target}` where the contract requires `elif multiple: opened.add(target)`.","sha256":"2a4fa7970084edb8f41c8f768f656c899ca28306c9cd569d29b911b13b485daa","title":"Accordion open-panel state: Opening a second panel in multiple mode closes the first · 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":40.77,"exit_code":1,"observations":[{"actual":["a"],"check":"removed","expected":["a"],"passed":true},{"actual":["a"],"check":"unknown","expected":["a"],"passed":true},{"actual":["a"],"check":"locked","expected":["a"],"passed":true},{"actual":[],"check":"collapse","expected":[],"passed":true},{"actual":["a"],"check":"multiple","expected":["a","b"],"passed":false},{"actual":["b"],"check":"single","expected":["b"],"passed":true},{"actual":[0],"check":"parameterized panels","expected":[0,1],"passed":false},{"actual":["b"],"check":"repeat single","expected":["b"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"removed\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"unknown\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"locked\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"collapse\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"multiple\", \"actual\": [\"a\"], \"expected\": [\"a\", \"b\"], \"passed\": false}, {\"check\": \"single\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"passed\": true}, {\"check\": \"parameterized panels\", \"actual\": [0], \"expected\": [0, 1], \"passed\": false}, {\"check\": \"repeat single\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.425,"exit_code":1,"observations":[{"actual":["a"],"check":"removed","expected":["a"],"passed":true},{"actual":["a"],"check":"unknown","expected":["a"],"passed":true},{"actual":["a"],"check":"locked","expected":["a"],"passed":true},{"actual":[],"check":"collapse","expected":[],"passed":true},{"actual":["b"],"check":"multiple","expected":["a","b"],"passed":false},{"actual":["b"],"check":"single","expected":["b"],"passed":true},{"actual":[1],"check":"parameterized panels","expected":[0,1],"passed":false},{"actual":["b"],"check":"repeat single","expected":["b"],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"removed\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"unknown\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"locked\", \"actual\": [\"a\"], \"expected\": [\"a\"], \"passed\": true}, {\"check\": \"collapse\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"multiple\", \"actual\": [\"b\"], \"expected\": [\"a\", \"b\"], \"passed\": false}, {\"check\": \"single\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"passed\": true}, {\"check\": \"parameterized panels\", \"actual\": [1], \"expected\": [0, 1], \"passed\": false}, {\"check\": \"repeat single\", \"actual\": [\"b\"], \"expected\": [\"b\"], \"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."}}