See [this ticket](https://github.com/unisonweb/unison/issues/849).

``` unison
x = 42

> x
```

``` ucm

  Loading changes detected in scratch.u.

  I found and typechecked these definitions in scratch.u. If you
  do an `add` or `update`, here's how your codebase would
  change:
  
    ⍟ These new definitions are ok to `add`:
    
      x : Nat
  
  Now evaluating any watch expressions (lines starting with
  `>`)... Ctrl+C cancels.

    3 | > x
          ⧩
          42

```