# Operation Extension Without Element Change

> The ability to add new operations over a structure without modifying its element classes.

Record: `lexicon:operation-extension-without-element-change`
Kind: capability
Layer: [Design Patterns Core](https://banes-lab.com/records/layer/design-patterns-core.md)
Canonical: https://banes-lab.com/ontology/lexicon#lexicon-operation-extension-without-element-change

Listed in [Lexicon terms](https://banes-lab.com/api/records/lexicon.md), after [Null-Check Elimination](https://banes-lab.com/records/lexicon/null-check-elimination.md) and before [Ordered Fallthrough](https://banes-lab.com/records/lexicon/ordered-fallthrough.md).

## Category

- [Behavioral Patterns](https://banes-lab.com/records/lexicon-category/behavioral-patterns.md)

## Enabled by

- [Visitor Pattern](https://banes-lab.com/records/architecture/visitor-pattern.md)

## Linked from

- [Behavioral Patterns](https://banes-lab.com/ontology/principles/architecture-category-behavioral-patterns.md)