Smoking Pack-Year Calculator

Inspectable records

Ledger state

The current ledger marks this instrument verified clean within the source-bound verification corpus.

Area

Biology, Medicine & Pharmacology (educational estimates only — every panel labeled not-medical-advice)

Tranche

tranche-5

Evidence ID

t5-068

Ledger rows

1

No ledger note is attached.

Review findings

The honest-label language is appropriate, but the specification must resolve the exact ambiguity between cigarettes/day and packs/day and explicitly define the pack-size assumption before release.

Formula and scope findings

• The stated formula is correct only when the input is packs per day, but the specified input is cigarettes per day; cigarettes/day must be divided by cigarettes per pack first.
• The pack size is unspecified. A 20-cigarette pack is a common convention, but pack sizes vary, so the instrument must state or collect the assumed pack size.
• For multiple smoking periods, the formula must sum each period: total pack-years = sum((cigarettes/day ÷ cigarettes/pack) × years) rather than applying one undifferentiated period formula.

Unit assumptions

• Unless otherwise specified, one pack is assumed to contain 20 cigarettes.
• Years smoked are elapsed years and must be nonnegative; fractional years are allowed.
• Cigarettes/day must be nonnegative and cigarettes/pack must be a positive integer.
• Pack-years means packs per day multiplied by years, with output units of pack-years.

Boundary hardening

BREAK_CLAIMED · SELF_FLAGGED

The specification does not define the cigarettes-per-pack conversion, so the same cigarette history can produce different totals. Extreme finite inputs also overflow ordinary JavaScript arithmetic to Infinity, which requires validation or rejection.

Errata and corrections

No applied erratum is attached to this unique-name record.

Inspectable example

4 review vectors are recorded. One source-bound sample is shown below.

{
  "inputs": {
    "cigarettes_per_day": 20,
    "years_smoked": 15,
    "assumed_cigarettes_per_pack": 20
  },
  "expected_outputs": {
    "total_pack_years": 15
  },
  "working": "packs/day = 20 cigarettes/day ÷ 20 cigarettes/pack = 1 pack/day; pack-years = 1 × 15 years = 15 pack-years."
}

Related workflows

No source-defined multi-instrument workflow membership is recorded.

Sources and evidence

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

• VERIFIED_LEDGER.json · VERIFIED_CLEAN
• evidence-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json