# Clarify behaviour of typeintersect()

**URL:** https://discourse.julialang.org/t/clarify-behaviour-of-typeintersect/63097
**Category:** General Usage
**Created:** [June 17, 2021, 3:03pm UTC](https://discourse.julialang.org/t/clarify-behaviour-of-typeintersect/63097 "2021-06-17T15:03:00Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![cjdoris](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/cjdoris/32/213133_2.png) [@cjdoris](https://discourse.julialang.org/u/cjdoris)
#### Post date: [June 17, 2021, 3:03pm UTC](https://discourse.julialang.org/t/clarify-behaviour-of-typeintersect/63097/1 "2021-06-17T15:03:00Z")

</div>

The docs say:

> ```
> typeintersect(T, S)
> 
> ```
> 
> Compute a type that contains the intersection of T and S. Usually this will be the smallest such type or one close to it.

I interpret this to mean that there may be cases where `typeintersect(T, S)` is not a subtype of both `T` and `S`?

Can anyone give me an example?