---
slug: "SpecBinding"
name: "SpecBinding"
type: "Reasoning"
layer: "Mind"
ref: "SpecBinding#16e5"
sema_id: "sema:SpecBinding#mh:SHA-256:16e5d03844bf2b95629b6fedc9f9067d2611a701431dc6f933395e7f0911f2e5"
tags: ["Mind","Reasoning"]
updated: 2026-11-11
mindscape: "bootstrap"
index_url: https://mindscape.pages.dev/bootstrap/index.json
url: https://mindscape.pages.dev/bootstrap/SpecBinding/
related: ["MeaningChangeSweep","Spec","Verification","SpecIntentCheck","Trace#b68d"]
---

# SpecBinding

Bind an implementation to an external specification by a pinned version, a two-way map and a ledger of deviations

Layer: Mind · Category: Reasoning

## Mechanism

An implementation, such as code, a procedure or a set of controls, is bound to an external [Spec](https://mindscape.pages.dev/bootstrap/Spec.md), such as a paper, a standard, a regulation or a design document, in four ways. One document is named authoritative and its exact version pinned, such as a commit, an edition or a dated consolidated text. Every restatement, summary, comment or test is marked as derived, never as a second source. A two-way map links each rule of the specification to the part of the implementation that carries it out, and links each consequential part to the rule it serves or to a recorded implementation choice; the binding states its criterion for what is consequential. A deviation ledger records rules not implemented, choices the specification leaves open (precision, rounding, ordering, or how a vague clause is read) and places where the implementation knowingly differs. When the pin or a mapped part changes, the map is checked again before the change is accepted, and a value whose meaning changes is swept as in [MeaningChangeSweep](https://mindscape.pages.dev/bootstrap/MeaningChangeSweep.md). [Verification](https://mindscape.pages.dev/bootstrap/Verification.md) against the binding establishes conformance to the pinned version only, not that the specification is right.

## Invariants

- Exactly one source is authoritative for each rule, and its version is pinned.
- Every specification rule maps to part of the implementation, to a test, or to a ledger entry stating why it does not.
- Every part of the implementation that the binding's stated criterion marks as consequential maps to a rule or to a recorded implementation choice.
- A change to the pin or to a mapped part of the implementation triggers the map check before the change is accepted.

## Failure modes

- Floating pin: the implementation cites the specification without a version, so a later edit silently changes what it claims to implement.
- Second source: a summary, a lighter edition or a test suite drifts and is treated as authoritative.
- One-way map: rules map to the implementation, but consequential parts of it map to nothing, so unspecified behaviour stays hidden.
- Ledger rot: a recorded deviation, comment or test keeps describing an implementation or meaning that has since changed.

## Builds on

- [MeaningChangeSweep](https://mindscape.pages.dev/bootstrap/MeaningChangeSweep.md) (Mind; References)
- [Spec](https://mindscape.pages.dev/bootstrap/Spec.md) (Infrastructure; References)
- [Verification](https://mindscape.pages.dev/bootstrap/Verification.md) (Mind; References)

## Used by

—

## Identity

- Sema ID: `sema:SpecBinding#mh:SHA-256:16e5d03844bf2b95629b6fedc9f9067d2611a701431dc6f933395e7f0911f2e5`
- Ref: `SpecBinding#16e5`

## Links

- [Pattern page](https://mindscape.pages.dev/bootstrap/SpecBinding/)
- [View in the interactive graph](https://mindscape.pages.dev/bootstrap/#SpecBinding)
- [JSON](https://mindscape.pages.dev/bootstrap/SpecBinding.json)
- [Index of all patterns](https://mindscape.pages.dev/bootstrap/index.json)