``` unison
unique type Foo = Bar Nat
```

``` 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`:
    
      type Foo

```
``` ucm
scratch/main> add

  ⍟ I've added these definitions:
  
    type Foo

scratch/main> alias.term Foo.Bar Foo.BarAlias

  Done.

```
``` unison
unique type Foo = Bar Nat Nat
```

``` 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 names already exist. You can `update` them to your
      new definition:
    
      type Foo

```
``` ucm
scratch/main> update

  Sorry, I wasn't able to perform the update:
  
  The type Foo has a constructor with multiple names, and I
  can't perform an update in this situation:
  
    * Foo.Bar
    * Foo.BarAlias
  
  Please delete all but one name for each constructor, and then
  try updating again.

```