{"abstract":"Express lane dynamic price returns a wrong result when price decreases are not rate limited.","category":"Toll and parking fee computation","checks":8,"contract":"Input {density, prev_price, bands: [[density upto, price]] ascending, max_step, min_price, max_price, occupancy, hov_free_min, hov2_pct}. The target is the first band whose upto is >= density, else max_price. The posted price moves from prev_price toward the target by at most max_step either way, then is clamped to [min_price, max_price]. Vehicles with occupancy >= hov_free_min pay 0; occupancy 2 (when not free) pays hov2_pct percent floored to 5 cents. Return [posted, charged].","contract_signature":"x","evaluation_group":"w2-toll_and_parking_fee_computation-express-lane-price","failed_approach":"Taking the absolute difference always moves the price upward.","family":"w2-toll_and_parking_fee_computation-express-lane-price-rate-limit","id":"FA-68566","implementations":{"attempt":{"sha256":"f4cf805e9bf402b1fc0701a6b884086f64158e595e9ebb4c7a0cb4c682abe1d1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    target = x['max_price']\n    for upto, price in x['bands']:\n        if x['density'] <= upto:\n            target = price\n            break\n    prev = x['prev_price']\n    step = max(-x['max_step'], min(x['max_step'], abs(target - prev)))\n    price = max(x['min_price'], min(x['max_price'], prev + step))\n    if x['occupancy'] >= x['hov_free_min']:\n        return [price, 0]\n    if x['occupancy'] == 2:\n        return [price, price * x['hov2_pct'] // 100 // 5 * 5]\n    return [price, price]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 13, 'prev_price': 1250, 'bands': [[10, 50], [13, 550], [18, 750], [26, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 560]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 44, 'prev_price': 1050, 'bands': [[23, 125], [24, 150], [40, 350], [44, 450]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 2, 'hov2_pct': 70}, [1000, 0]), ({'density': 21, 'prev_price': 825, 'bands': [[21, 300], [28, 325], [35, 750], [36, 850]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 4, 'hov2_pct': 70}, [800, 800]), ({'density': 35, 'prev_price': 1150, 'bands': [[20, 100], [25, 150], [34, 625], [35, 800]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 70}, [1000, 0]), ({'density': 15, 'prev_price': 875, 'bands': [[12, 150], [15, 475], [30, 550], [44, 600]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 4, 'hov2_pct': 50}, [850, 850]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50])], [({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 11, 'prev_price': 425, 'bands': [[11, 250], [17, 600], [38, 775], [41, 850]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 70}, [325, 0]), ({'density': 44, 'prev_price': 375, 'bands': [[16, 250], [22, 325], [30, 675], [44, 750]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 50}, [400, 0]), ({'density': 24, 'prev_price': 1225, 'bands': [[24, 50], [28, 700], [30, 800], [44, 925]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 50}, [800, 0]), ({'density': 32, 'prev_price': 600, 'bands': [[12, 250], [13, 275], [21, 475], [32, 700]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 50}, [625, 0]), ({'density': 42, 'prev_price': 1225, 'bands': [[11, 125], [21, 325], [42, 850], [44, 1000]], 'max_step': 50, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1175, 1175]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245])], [({'density': 25, 'prev_price': 1100, 'bands': [[13, 175], [18, 325], [20, 350], [37, 650]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 4, 'hov2_pct': 50}, [1000, 1000]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 23, 'prev_price': 525, 'bands': [[11, 225], [17, 450], [23, 625], [27, 925]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 50}, [625, 0]), ({'density': 38, 'prev_price': 1125, 'bands': [[19, 375], [23, 775], [36, 900], [38, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [1025, 1025]), ({'density': 3, 'prev_price': 425, 'bands': [[12, 275], [34, 850], [38, 875], [40, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 1, 'hov_free_min': 2, 'hov2_pct': 50}, [325, 325]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 37, 'prev_price': 700, 'bands': [[16, 175], [17, 200], [22, 300], [37, 675]], 'max_step': 50, 'min_price': 50, 'max_price': 1200, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 70}, [675, 0])], [({'density': 17, 'prev_price': 100, 'bands': [[10, 125], [17, 325], [30, 675], [41, 750]], 'max_step': 50, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 4, 'hov2_pct': 70}, [150, 105]), ({'density': 15, 'prev_price': 975, 'bands': [[15, 125], [18, 250], [42, 525], [43, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 560]), ({'density': 23, 'prev_price': 1050, 'bands': [[14, 100], [15, 175], [23, 575], [32, 700]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 0]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 27, 'prev_price': 625, 'bands': [[19, 75], [27, 250], [33, 450], [36, 775]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [525, 525]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 23, 'prev_price': 725, 'bands': [[20, 275], [23, 350], [34, 675], [35, 750]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 4, 'hov2_pct': 70}, [675, 675]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245])], [({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 30, 'prev_price': 175, 'bands': [[18, 325], [27, 425], [28, 575], [42, 875]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [275, 275]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 42, 'prev_price': 375, 'bands': [[11, 175], [26, 375], [32, 650], [42, 950]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 70}, [475, 0]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 23, 'prev_price': 750, 'bands': [[13, 325], [23, 450], [39, 850], [44, 875]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 4, 'hov2_pct': 50}, [650, 325]), ({'density': 21, 'prev_price': 900, 'bands': [[17, 75], [21, 100], [25, 400], [35, 625]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 0]), ({'density': 20, 'prev_price': 900, 'bands': [[20, 50], [26, 400], [28, 525], [43, 750]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 4, 'hov_free_min': 4, 'hov2_pct': 70}, [800, 0])]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check('fee oracle' + ' %d' % i, 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":"6471357311ca6b8ea0ee1760f17147a82b1de16479d0f2e4a27215ef033561af","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    target = x['max_price']\n    for upto, price in x['bands']:\n        if x['density'] <= upto:\n            target = price\n            break\n    prev = x['prev_price']\n    step = min(x['max_step'], target - prev)\n    price = max(x['min_price'], min(x['max_price'], prev + step))\n    if x['occupancy'] >= x['hov_free_min']:\n        return [price, 0]\n    if x['occupancy'] == 2:\n        return [price, price * x['hov2_pct'] // 100 // 5 * 5]\n    return [price, price]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 13, 'prev_price': 1250, 'bands': [[10, 50], [13, 550], [18, 750], [26, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 560]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 44, 'prev_price': 1050, 'bands': [[23, 125], [24, 150], [40, 350], [44, 450]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 2, 'hov2_pct': 70}, [1000, 0]), ({'density': 21, 'prev_price': 825, 'bands': [[21, 300], [28, 325], [35, 750], [36, 850]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 4, 'hov2_pct': 70}, [800, 800]), ({'density': 35, 'prev_price': 1150, 'bands': [[20, 100], [25, 150], [34, 625], [35, 800]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 70}, [1000, 0]), ({'density': 15, 'prev_price': 875, 'bands': [[12, 150], [15, 475], [30, 550], [44, 600]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 4, 'hov2_pct': 50}, [850, 850]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50])], [({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 11, 'prev_price': 425, 'bands': [[11, 250], [17, 600], [38, 775], [41, 850]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 70}, [325, 0]), ({'density': 44, 'prev_price': 375, 'bands': [[16, 250], [22, 325], [30, 675], [44, 750]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 50}, [400, 0]), ({'density': 24, 'prev_price': 1225, 'bands': [[24, 50], [28, 700], [30, 800], [44, 925]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 50}, [800, 0]), ({'density': 32, 'prev_price': 600, 'bands': [[12, 250], [13, 275], [21, 475], [32, 700]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 50}, [625, 0]), ({'density': 42, 'prev_price': 1225, 'bands': [[11, 125], [21, 325], [42, 850], [44, 1000]], 'max_step': 50, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1175, 1175]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245])], [({'density': 25, 'prev_price': 1100, 'bands': [[13, 175], [18, 325], [20, 350], [37, 650]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 3, 'hov_free_min': 4, 'hov2_pct': 50}, [1000, 1000]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 23, 'prev_price': 525, 'bands': [[11, 225], [17, 450], [23, 625], [27, 925]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 50}, [625, 0]), ({'density': 38, 'prev_price': 1125, 'bands': [[19, 375], [23, 775], [36, 900], [38, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [1025, 1025]), ({'density': 3, 'prev_price': 425, 'bands': [[12, 275], [34, 850], [38, 875], [40, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 1, 'hov_free_min': 2, 'hov2_pct': 50}, [325, 325]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 37, 'prev_price': 700, 'bands': [[16, 175], [17, 200], [22, 300], [37, 675]], 'max_step': 50, 'min_price': 50, 'max_price': 1200, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 70}, [675, 0])], [({'density': 17, 'prev_price': 100, 'bands': [[10, 125], [17, 325], [30, 675], [41, 750]], 'max_step': 50, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 4, 'hov2_pct': 70}, [150, 105]), ({'density': 15, 'prev_price': 975, 'bands': [[15, 125], [18, 250], [42, 525], [43, 975]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 560]), ({'density': 23, 'prev_price': 1050, 'bands': [[14, 100], [15, 175], [23, 575], [32, 700]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 3, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 0]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 27, 'prev_price': 625, 'bands': [[19, 75], [27, 250], [33, 450], [36, 775]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [525, 525]), ({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 23, 'prev_price': 725, 'bands': [[20, 275], [23, 350], [34, 675], [35, 750]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 4, 'hov2_pct': 70}, [675, 675]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245])], [({'density': 45, 'prev_price': 1100, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [1000, 1000]), ({'density': 30, 'prev_price': 175, 'bands': [[18, 325], [27, 425], [28, 575], [42, 875]], 'max_step': 100, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 70}, [275, 275]), ({'density': 25, 'prev_price': 0, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 25, 'min_price': 50, 'max_price': 1000, 'occupancy': 1, 'hov_free_min': 3, 'hov2_pct': 50}, [50, 50]), ({'density': 42, 'prev_price': 375, 'bands': [[11, 175], [26, 375], [32, 650], [42, 950]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 4, 'hov_free_min': 2, 'hov2_pct': 70}, [475, 0]), ({'density': 20, 'prev_price': 300, 'bands': [[12, 100], [20, 400], [30, 700], [40, 900]], 'max_step': 50, 'min_price': 50, 'max_price': 1000, 'occupancy': 2, 'hov_free_min': 3, 'hov2_pct': 70}, [350, 245]), ({'density': 23, 'prev_price': 750, 'bands': [[13, 325], [23, 450], [39, 850], [44, 875]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 2, 'hov_free_min': 4, 'hov2_pct': 50}, [650, 325]), ({'density': 21, 'prev_price': 900, 'bands': [[17, 75], [21, 100], [25, 400], [35, 625]], 'max_step': 100, 'min_price': 50, 'max_price': 800, 'occupancy': 4, 'hov_free_min': 3, 'hov2_pct': 70}, [800, 0]), ({'density': 20, 'prev_price': 900, 'bands': [[20, 50], [26, 400], [28, 525], [43, 750]], 'max_step': 100, 'min_price': 50, 'max_price': 1200, 'occupancy': 4, 'hov_free_min': 4, 'hov2_pct': 70}, [800, 0])]]\nfor i, (args, expected) in enumerate(fixtures[N-1]):\n    check('fee oracle' + ' %d' % i, 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, bounded toy model with a stipulated contract; it makes no claim of conformance to any agency manual or standard. 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-toll_and_parking_fee_computation-express-lane-price-rate-limit","generated_at":"2026-09-29T14:48:03.466382+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Fee engines bill customers in integer cents; a wrong boundary, rounding stage or cap scope silently over- or under-charges.","root_cause":"Only increases are limited, so the price can collapse in a single interval.","sha256":"7ba9c27dbd581d3569d1430500c590d681ac561af356428140cb2bd632fa62e5","title":"Express lane dynamic price: price decreases are not rate limited · 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":43.947,"exit_code":1,"observations":[{"actual":[1000,1000],"check":"fee oracle 0","expected":[1000,1000],"passed":true},{"actual":[800,560],"check":"fee oracle 1","expected":[800,560],"passed":true},{"actual":[350,245],"check":"fee oracle 2","expected":[350,245],"passed":true},{"actual":[1000,0],"check":"fee oracle 3","expected":[1000,0],"passed":true},{"actual":[850,850],"check":"fee oracle 4","expected":[800,800],"passed":false},{"actual":[1000,0],"check":"fee oracle 5","expected":[1000,0],"passed":true},{"actual":[900,900],"check":"fee oracle 6","expected":[850,850],"passed":false},{"actual":[50,50],"check":"fee oracle 7","expected":[50,50],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fee oracle 0\", \"actual\": [1000, 1000], \"expected\": [1000, 1000], \"passed\": true}, {\"check\": \"fee oracle 1\", \"actual\": [800, 560], \"expected\": [800, 560], \"passed\": true}, {\"check\": \"fee oracle 2\", \"actual\": [350, 245], \"expected\": [350, 245], \"passed\": true}, {\"check\": \"fee oracle 3\", \"actual\": [1000, 0], \"expected\": [1000, 0], \"passed\": true}, {\"check\": \"fee oracle 4\", \"actual\": [850, 850], \"expected\": [800, 800], \"passed\": false}, {\"check\": \"fee oracle 5\", \"actual\": [1000, 0], \"expected\": [1000, 0], \"passed\": true}, {\"check\": \"fee oracle 6\", \"actual\": [900, 900], \"expected\": [850, 850], \"passed\": false}, {\"check\": \"fee oracle 7\", \"actual\": [50, 50], \"expected\": [50, 50], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.224,"exit_code":1,"observations":[{"actual":[1000,1000],"check":"fee oracle 0","expected":[1000,1000],"passed":true},{"actual":[550,385],"check":"fee oracle 1","expected":[800,560],"passed":false},{"actual":[350,245],"check":"fee oracle 2","expected":[350,245],"passed":true},{"actual":[450,0],"check":"fee oracle 3","expected":[1000,0],"passed":false},{"actual":[300,300],"check":"fee oracle 4","expected":[800,800],"passed":false},{"actual":[800,0],"check":"fee oracle 5","expected":[1000,0],"passed":false},{"actual":[475,475],"check":"fee oracle 6","expected":[850,850],"passed":false},{"actual":[50,50],"check":"fee oracle 7","expected":[50,50],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fee oracle 0\", \"actual\": [1000, 1000], \"expected\": [1000, 1000], \"passed\": true}, {\"check\": \"fee oracle 1\", \"actual\": [550, 385], \"expected\": [800, 560], \"passed\": false}, {\"check\": \"fee oracle 2\", \"actual\": [350, 245], \"expected\": [350, 245], \"passed\": true}, {\"check\": \"fee oracle 3\", \"actual\": [450, 0], \"expected\": [1000, 0], \"passed\": false}, {\"check\": \"fee oracle 4\", \"actual\": [300, 300], \"expected\": [800, 800], \"passed\": false}, {\"check\": \"fee oracle 5\", \"actual\": [800, 0], \"expected\": [1000, 0], \"passed\": false}, {\"check\": \"fee oracle 6\", \"actual\": [475, 475], \"expected\": [850, 850], \"passed\": false}, {\"check\": \"fee oracle 7\", \"actual\": [50, 50], \"expected\": [50, 50], \"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."}}