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## choice

Basis Function

Use a Boolean value to select one of two items.

       a b false choice
    ----------------------
              a

       a b true choice
    ---------------------
              b

### Definition

> \[[pop]\] \[[popd]\] [branch]

### Discussion

It's a matter of taste whether you implement this in terms of [branch] or
the other way around.

### Crosslinks

[branch]
[select]

