> For the complete documentation index, see [llms.txt](https://docs.snomed.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.snomed.org/snomed-international-documents/snomed-ct-glossary/i/intersection.md).

# intersection

## intersection

The set of elements that are members of **both** of two specified sets.

#### Notes

* In set theory, the *intersection* of sets \*\* *A*\*\* and ***B*** refers to all elements that are in both set ***A*** and set ***B***.
* In SNOMED CT, the *intersection* of two \_subsets \_of concepts consists of all concepts that are members of both subsets.

#### Examples

* The following expression constraint language defines the set of concepts that in the intersection subtypes of [85562004 | Hand|](http://snomed.info/id/85562004) and members or the [723264001 | Lateralizable body structure reference set|](http://snomed.info/id/723264001) . The "AND" instruction indicates a union between the sets defined by constraints on either side of that instruction.

< [85562004 |Hand|](http://snomed.info/id/85562004)\
AND ^ [723264001 |Lateralizable body structure reference set|](http://snomed.info/id/723264001)

## Related Links

* Wikipedia
  * [Intersection (set theory)](https://en.wikipedia.org/wiki/Intersection_\(set_theory\))

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