Modular Arithmetic Toolkit 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

t4-069

Effect

Computation or source lookup only

Input and validation requirements

The test set exposes two required safeguards: modulus zero must be rejected because modular reduction is undefined, and congruence solving must branch on whether gcd(a,m) divides b. Negative operands also expose a convention hazard if canonical residues are not distinguished from signed language-level remainders.

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": "add",
    "values": [
      37,
      -14
    ],
    "modulus": 10
  },
  "expected_outputs": {
    "result": 3
  },
  "working": "37 + (-14) = 23. 23 = 2·10 + 3, so 23 mod 10 = 3."
}

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