Source: https://guthlabs.ai/docs/instruments/shannon-entropy-information-content-calculator/implementation/

instrument implementation / implementation-contract

# Shannon Entropy / Information Content Calculator implementation

A source-bound implementation contract for Shannon Entropy / Information Content 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**: t4-148

**Effect**: Computation or source lookup only

## Input and validation requirements

The specification does not define validation behavior for negative or out-of-range probabilities, zero-probability self-information, the normalized redundancy 0/0 case, or text conventions such as case sensitivity. These can produce rejection requirements, infinities, undefined values, or materially different entropy results.

## 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": {
    "mode": "probability_list",
    "symbols": [
      "H",
      "T"
    ],
    "probabilities": [
      0.5,
      0.5
    ]
  },
  "expected_outputs": {
    "entropy_bits_per_symbol": 1,
    "frequency_table": [
      {
        "symbol": "H",
        "probability": 0.5
      },
      {
        "symbol": "T",
        "probability": 0.5
      }
    ],
    "self_information_bits": {
      "H": 1,
      "T": 1
    },
    "maximum_entropy_bits_per_symbol": 1,
    "redundancy_bits_per_symbol": 0,
    "normalized_redundancy_percent": 0
  },
  "working": "H=-(0.5×log2(0.5)+0.5×log2(0.5))=-(0.5×(-1)+0.5×(-1))=1 bit/symbol. I(H)=-log2(0.5)=1 bit and I(T)=-log2(0.5)=1 bit. M=2, so Hmax=log2(2)=1. Absolute redundancy=1-1=0 bits/symbol. Normalized redundancy=1-(1/1)=0=0%."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/shannon-entropy-information-content-calculator/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/shannon-entropy-information-content-calculator/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/shannon-entropy-information-content-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-tranche4/tranche4-results.json`