Source: https://guthlabs.ai/docs/instruments/comb-filtering-phase-cancellation-predictor/implementation/

instrument implementation / implementation-contract

# Comb Filtering / Phase Cancellation Predictor implementation

A source-bound implementation contract for Comb Filtering / Phase Cancellation Predictor; 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**: t4-061

**Effect**: Computation or source lookup only

## Input and validation requirements

The predictor reaches an undefined division-by-zero condition when the path-length difference is exactly zero and can produce physically invalid negative frequencies if a signed time or distance difference is used without an absolute-value 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": {
    "delta_d_m": 0.5,
    "speed_of_sound_m_per_s": 343,
    "null_n": [
      1,
      3,
      5
    ],
    "peak_n": [
      2,
      4
    ]
  },
  "expected_outputs": {
    "null_frequencies_hz": [
      343,
      1029,
      1715
    ],
    "peak_frequencies_hz": [
      686,
      1372
    ]
  },
  "working": "Base frequency = c/(2*Δd) = 343/(2*0.5) = 343/1 = 343 Hz. Nulls use odd n: n=1 -> 1*343 = 343 Hz; n=3 -> 3*343 = 1029 Hz; n=5 -> 5*343 = 1715 Hz. Peaks use even n: n=2 -> 2*343 = 686 Hz; n=4 -> 4*343 = 1372 Hz."
}
````

## Other records

[01**Overview**](<https://guthlabs.ai/docs/instruments/comb-filtering-phase-cancellation-predictor/>)[02**Mechanism**](<https://guthlabs.ai/docs/instruments/comb-filtering-phase-cancellation-predictor/mechanism/>)[04**Qualification**](<https://guthlabs.ai/docs/instruments/comb-filtering-phase-cancellation-predictor/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`