Source: https://guthlabs.ai/docs/instruments/firewood-cord-calculator/implementation/

instrument implementation / implementation-contract

# Firewood / Cord Calculator implementation

A source-bound implementation contract for Firewood / Cord Calculator; deployment and executable qualification remain separate.

Status: **VERIFIED_CLEAN**Lifecycle: **implementation-contract**

## 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**: t5-120

**Effect**: Computation or source lookup only

## Input and validation requirements

Very large finite-looking inputs overflow JavaScript arithmetic and produce Infinity rather than a finite cord value. Negative dimensions also produce a negative result unless physical-input validation rejects them.

## 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": {
    "L_ft": 8,
    "W_ft": 4,
    "H_ft": 4
  },
  "expected_outputs": {
    "cords": 1
  },
  "working": "Volume = 8 ft × 4 ft × 4 ft = 128 ft³. Cords = 128 ÷ 128 = 1 cord."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/firewood-cord-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/firewood-cord-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/firewood-cord-calculator/qualification/>)

## 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`