GC Content & Sequence Composition Analyzer 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

t5-141

Effect

Computation or source lookup only

Input and validation requirements

The specification does not define behavior for an empty sequence, causing GC% and AT% to require division by zero. It also does not define RNA U handling or the denominator policy for ambiguous symbols such as N, so different reasonable implementations can produce different outputs.

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": {
    "sequence": "ATGC"
  },
  "expected_outputs": {
    "gc_percent": 50,
    "at_percent": 50,
    "base_counts": {
      "A": 1,
      "T": 1,
      "G": 1,
      "C": 1
    },
    "length": 4
  },
  "working": "Count A=1, T=1, G=1, C=1, so total=1+1+1+1=4. GC count=G+C=1+1=2. GC%=2/4×100=50%. AT count=A+T=1+1=2. AT%=2/4×100=50%. Length=4."
}

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