Explanation: You can ❰merge❱ the alternatives of a union using a record with one
handler per alternative, like this:


    ┌─────────────────────────────────────────────────────────────────────┐
    │     let union    = < Left = +2 | Right : Bool >                     │
    │ in  let handlers = { Left = Natural/even, Right = λ(x : Bool) → x } │
    │ in  merge handlers union : Bool                                     │
    └─────────────────────────────────────────────────────────────────────┘


... as long as each handler is a function

For example, the following expression is $_NOT valid:


    ┌─────────────────────────────────────────┐
    │ merge { Foo = True } < Foo = 1 > : Bool │
    └─────────────────────────────────────────┘
                    ⇧
                    Invalid: Not a function


Your handler for this alternative:

↳ $txt0

... has the following type:

↳ $txt1

... which is not the type of a function