Packing Weight Checker mechanism

Model scope

The arithmetic formulas are straightforward, but the specification is ambiguous about per-bag grouping, multiple-limit mapping, and whether overage means signed difference or clamped excess. Keep the honest label: airline baggage limits vary and change; verify with the carrier before travel.

• total_weight = Σ(item weights) is correct only when all item weights use the same unit and belong to the same bag or explicitly defined group.
• The specification requests pass/fail per bag, but it does not define the bag structure, how items are assigned to bags, or how multiple limits correspond to bags.
• overage = total_weight − limit is a signed difference. When under the limit it produces a negative value, whereas an 'overage amount' is usually defined as max(0, total_weight − limit). The product must label this as signed difference or change the formula.
• The pass/fail rule is not explicitly stated; it should be PASS when total_weight <= limit and FAIL when total_weight > limit.

Units and conventions

• Every item weight and its applicable limit must use the same unit; no automatic conversion is specified.
• The test vectors use the declared unit exactly, including grams rather than implicitly treating gram values as kilograms.
• Weights and limits are assumed to be numeric and nonnegative.
• A single bag is assumed in each vector because per-bag grouping and multiple-limit mapping are not defined.
• The signed overage formula is used as written; negative outputs mean unused capacity, not a positive overage amount.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "bags": [
      {
        "id": "bag_1",
        "items": [
          {
            "name": "clothes",
            "weight": 2.4
          },
          {
            "name": "shoes",
            "weight": 1.8
          },
          {
            "name": "toiletries",
            "weight": 3.1
          }
        ],
        "limit": 8
      }
    ],
    "unit": "kg"
  },
  "expected_outputs": {
    "total_weight": 7.3,
    "pass_fail_per_bag": {
      "bag_1": "PASS"
    },
    "overage": -0.7
  },
  "working": "total_weight = 2.4 + 1.8 + 3.1 = 4.2 + 3.1 = 7.3 kg. overage = 7.3 − 8.0 = −0.7 kg. Since 7.3 <= 8.0, bag_1 = PASS."
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The extreme-magnitude vector produces Infinity in JavaScript, and the negative-weight vector exposes an input-validation and sign-convention hazard. The checker should reject non-finite values, negative physical item weights, and mixed or unlabeled units before calculating totals.

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json
• BOUNDARY_HAZARD_CATALOG.json