Source: https://guthlabs.ai/docs/instruments/ingredient-substitution-ratio-calculator/implementation/

instrument implementation / implementation-contract

# Ingredient Substitution Ratio Calculator implementation

A source-bound implementation contract for Ingredient Substitution Ratio 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**: t7-029

**Effect**: Computation or source lookup only

## Input and validation requirements

An extreme finite input of 1×10^308 tsp with a ratio of 3 produces 3×10^308, which overflows a standard finite floating-point result to +Infinity. Negative quantities also expose a convention hazard because the formula accepts them algebraically although a culinary calculator should reject 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": {
    "original_ingredient": "butter",
    "original_quantity": 1,
    "original_unit": "cup",
    "desired_substitute": "neutral cooking oil"
  },
  "expected_outputs": {
    "substitute_quantity": 0.75,
    "substitute_unit": "cup",
    "notes": "Use approximately 3/4 cup oil for 1 cup butter; texture and flavor may differ."
  },
  "reference_data": {
    "table_entry": "1 cup butter -> 3/4 cup neutral cooking oil",
    "ratio": 0.75,
    "source_convention": "widely tabulated standard culinary substitution value; Joy of Cooking-style convention"
  },
  "working": "orig_qty × ratio = 1 cup × 0.75 = 0.75 cup. Therefore substitute quantity = 3/4 cup oil."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/ingredient-substitution-ratio-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/ingredient-substitution-ratio-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/ingredient-substitution-ratio-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-tranche7/tranche7-results.json`