---
slug: "Reversibility"
name: "Reversibility"
type: "Primitives"
layer: "Physics"
ref: "Reversibility#cb35"
sema_id: "sema:Reversibility#mh:SHA-256:cb359b693e6f3e674083df81b207143179d19330d5c3ce6e1832674901074b37"
tags: ["Physics","Primitives"]
updated: 2026-11-11
mindscape: "bootstrap"
index_url: https://mindscape.world/scapes/bootstrap.json
url: https://mindscape.world/bootstrap/Reversibility/
related: ["Constraint","ReversibilityCheck","Translate","Trialhaven","Trialhaven#da45","ErrorCostAsymmetry"]
---

# Reversibility

Condition: Can this action be undone?

Layer: Physics · Category: Primitives

## Mechanism

Evaluates whether the post-state of an action allows a return to the pre-state. Two tests in order: whether the information needed to reconstruct the pre-state still exists, and only then whether restoring it costs less than the caller's declared limit. Returns TRUE for Type 2 decisions (reversible) and FALSE for Type 1 (one-way doors).

## Invariants

- A post-state that destroyed the information yields FALSE at any cost limit.
- The verdict names the cost limit and information-loss tolerance it was judged against, both [Constraint](https://mindscape.world/scapes/bootstrap/Constraint.md)s supplied by the caller.

## Failure modes

- False reversibility: the action created externalities the pre-action analysis omitted.
- Cost drift: the tolerance was declared before the reversal is attempted.

## Parameters

- `cost_limit` (PositiveInteger, unspecified): Maximum acceptable cost to reverse, in a unit the caller states.

## Builds on

- [Constraint](https://mindscape.world/scapes/bootstrap/Constraint.md) (Infrastructure; References)

## Used by

- [ReversibilityCheck](https://mindscape.world/scapes/bootstrap/ReversibilityCheck.md) (Society; References)
- [Translate](https://mindscape.world/scapes/bootstrap/Translate.md) (Mind; References)
- [Trialhaven](https://mindscape.world/scapes/bootstrap/Trialhaven.md) (Society; References)

## Identity

- Sema ID: `sema:Reversibility#mh:SHA-256:cb359b693e6f3e674083df81b207143179d19330d5c3ce6e1832674901074b37`
- Ref: `Reversibility#cb35`
- Supersedes:
  - `sema:Reversibility#mh:SHA-256:049f5fd98135ec288888fa61056f65a7e46067b06eaa5e7cee7a7bd3bfef2f74`
  - `sema:Reversibility#mh:SHA-256:af6fad316d76d324d6c2ac02a69fc1f2f095bfc69a48c33578e599c431e9598e`

## Links

- [Pattern page](https://mindscape.world/bootstrap/Reversibility/)
- [View in the interactive graph](https://mindscape.world/bootstrap/#Reversibility)
- [JSON](https://mindscape.world/scapes/bootstrap/Reversibility.json)
- [Index of all patterns](https://mindscape.world/scapes/bootstrap.json)