Punnett-based Trihybrid/Multi-gene Probability Calculator mechanism

Model scope

The core product rule is standard under independent assortment for simultaneous per-locus events. The instrument cannot receive an unconditional PASS until it explicitly defines genotype versus phenotype inputs, decimal-versus-percent representation, validation of locus count, and the precise independence assumption. The educational and not-medical-advice labeling is appropriate, but it does not resolve those computational ambiguities.

• The product rule is correct only when the per-locus events are independent and the requested outcome is the simultaneous occurrence of one specified event at every locus.
• The specification alternates between genotype probability and phenotype probability. A phenotype probability can require summing multiple genotype probabilities before applying the product rule; the current formula does not define that case.
• The role of 'number of loci' is underspecified: it must equal the number of supplied per-locus probabilities, or the calculator must reject the input.
• The formula does not state whether probabilities are supplied as decimals from 0 to 1 or as percentages from 0 to 100.

Units and conventions

• Probabilities are dimensionless decimal fractions in the inclusive range 0 to 1; for example, 25% must be entered as 0.25.
• The number of loci is an integer of at least 3 and must equal the length of the per-locus probability list.
• Each per-locus probability refers to one specified genotype or one already-combined phenotype event.
• The loci assort independently; no linkage, epistasis, conditional dependence, or other dependence is included.
• The combined result is a decimal probability; multiply by 100 only when displaying it as a percentage.

Inspectable vector

One of 4 source-bound review vectors:

{
  "inputs": {
    "number_of_loci": 3,
    "per_locus_probabilities": [
      0.25,
      0.5,
      0.25
    ]
  },
  "expected_outputs": {
    "combined_probability": 0.03125,
    "combined_probability_percent": 3.125
  },
  "working": "P = 0.25 × 0.50 × 0.25\n0.25 × 0.50 = 0.125\n0.125 × 0.25 = 0.03125\n0.03125 × 100 = 3.125%"
}

Failure boundary

BREAK_CLAIMED · SELF_FLAGGED

The plain product rule has no division-by-zero trap and no genuine multi-regime formula branch, but an implementation without strict validation can return Infinity for extreme inputs and can accept values outside the probability domain. Percentage-versus-fraction ambiguity can also produce invalid results if units are not explicit.

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-tranche5/tranche5-results.json
• BOUNDARY_HAZARD_CATALOG.json