Source: https://guthlabs.ai/docs/instruments/long-division-long-multiplication-stepper/implementation/

instrument implementation / implementation-contract

# Long Division / Long Multiplication Stepper implementation

A source-bound implementation contract for Long Division / Long Multiplication Stepper; 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**: t2-009

**Effect**: Computation or source lookup only

## Input and validation requirements

A zero divisor produces an undefined result and must be rejected. Signed division also has a convention-dependent result unless the quotient and remainder sign rules are explicitly specified.

## 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": {
    "operation": "division",
    "dividend": 847,
    "divisor": 23
  },
  "expected_outputs": {
    "quotient": 36,
    "remainder": 19
  },
  "working": "23 goes into 84 three times: 3 × 23 = 69; 84 - 69 = 15. Bring down 7 to make 157. 23 goes into 157 six times: 6 × 23 = 138; 157 - 138 = 19. Therefore quotient = 36 and remainder = 19. Check: 23 × 36 + 19 = 828 + 19 = 847."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/long-division-long-multiplication-stepper/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/long-division-long-multiplication-stepper/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/long-division-long-multiplication-stepper/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-tranche2/tranche2-results.json`