Half-Life Calculator (multi-order) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-287

Effect

Computation or source lookup only

Input and validation requirements

The specification admits inputs that produce division by zero or physically invalid negative half-lives, and it does not define validation behavior for zero or negative rate constants. It also does not explicitly define handling of an order value at or between formula branches.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "order": "zero",
    "k": 0.02,
    "k_unit": "mol L^-1 s^-1",
    "A0": 0.1,
    "A0_unit": "mol L^-1"
  },
  "expected_outputs": {
    "t_half": 2.5,
    "t_unit": "s"
  },
  "working": "t½ = [A]0/(2k) = 0.100 mol L^-1 / (2 × 0.020 mol L^-1 s^-1) = 0.100 / 0.040 s = 2.50 s."
}

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