// Variable references $(VAR_NAME) are expanded using the container's environment. If a variable
  // cannot be resolved, the reference in the input string will be unchanged. Double $$ are reduced
  // to a single $, which allows for escaping the $(VAR_NAME) syntax: i.e. "$$(VAR_NAME)" will
  // produce the string literal "$(VAR_NAME)". Escaped references will never be expanded, regardless

## 0.110.3

### Docs

* 📝 Update references to Python version, FastAPI supports all the current versions, no need to make the version explicit. PR [#11496](https://github.com/tiangolo/fastapi/pull/11496) by [@tiangolo](https://github.com/tiangolo).

argument are substituted with the respective type arguments for those type
parameters until each type argument is free of bound type parameters.
</p>

<p>
If type arguments contain cyclic references to themselves
through bound type parameters, simplification and thus type
inference fails.
Otherwise, type inference succeeds.
</p>

<h4 id="Type_unification">Type unification</h4>

<p>