# No Side Effects

> The requirement that a function compute its result without observable side effects.

Record: `lexicon:no-side-effects`
Kind: constraint
Layer: [Computation Core](https://banes-lab.com/records/layer/computation-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-no-side-effects

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Deterministic Behavior](https://banes-lab.com/records/lexicon/deterministic-behavior.md) and before [Properties/Invariants](https://banes-lab.com/records/lexicon/properties-invariants.md).

## Category

- [Correctness / Determinism / Verification](https://banes-lab.com/records/lexicon-category/correctness-determinism-verification.md)

## Required by

- [Pure Functions](https://banes-lab.com/records/architecture/pure-functions.md)

## Linked from

- [Correctness / Determinism / Verification](https://banes-lab.com/ontology/principles/architecture-category-correctness-determinism-verification.md)
- [Core Vocabulary](https://banes-lab.com/ontology/lexicon/lexicon-category-core-vocabulary.md)