Binary/Text Diff & Similarity Ratio 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

t5-089

Effect

Computation or source lookup only

Input and validation requirements

The specified formula is undefined for two empty text blocks because max(len1,len2)=0, causing division by zero. The result is also convention-sensitive because case handling is unspecified, and the available LCS-based ratio can produce a different score from the Levenshtein formula.

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": {
    "text1": "cat",
    "text2": "cat"
  },
  "expected_outputs": {
    "edit_distance": 0,
    "similarity_percent": 100,
    "inline_diff": [
      {
        "op": "equal",
        "text": "cat"
      }
    ]
  },
  "working": "len1=3, len2=3; max(3,3)=3. Levenshtein distance=0 because the strings are identical. similarity=1-0/3=1. percent=1*100=100%. Diff: all 3 characters are equal."
}

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-tranche5/tranche5-results.json