> For the complete documentation index, see [llms.txt](https://trizen.gitbook.io/sidef-lang/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://trizen.gitbook.io/sidef-lang/programming_tasks/f/fork.md).

# Fork

```ruby
var x = 42
{ x += 1; say x }.fork.wait      # x is 43 here
say x                            # but here is still 42
```