IEEE-754 Float Inspector 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

t2-016

Effect

Computation or source lookup only

Input and validation requirements

The stated normal-number formula is invalid for zero, subnormals, infinities, and NaNs, and raw hexadecimal input is ambiguous without an explicit word-versus-byte-order convention.

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": {
    "decimal": 1.5,
    "precision": 64
  },
  "expected_outputs": {
    "sign_bits": "0",
    "exponent_bits": "01111111111",
    "mantissa_bits": "1000000000000000000000000000000000000000000000000000",
    "raw_hex": "0x3FF8000000000000",
    "decimal_reconstruction": 1.5,
    "ulp_error": 0
  },
  "working": "1.5 = 1 + 1/2 = 1.1₂. The unbiased exponent is 0, so E=0+1023=1023=01111111111₂. Sign s=0. The fraction field is 1000...000₂, or 0x8000000000000. Reconstruct: (+1)·(1+1/2)·2^0 = 1.5. The decimal input is exactly representable, so rounding error=1.5-1.5=0 and ULP error=0."
}

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-tranche2/tranche2-results.json