Adrian Baran

@leonbloy, @yanjankaf take a look at this section: [13.4.3.2 Use case for ==: comparing with undefined or null](https://exploringjs.com/impatient-js/ch_operators.html#use-case-for-comparing-with-undefined-or-null) for the explanation of why `if (x == null) { ... }`...

Here is what I needed to change in order to make the tests pass and code to compile (the diff is against `master` branch, `681531a`): https://github.com/rtfeldman/elm-in-action/pull/17

In "_Chapter 1: Introduction_" in ["_Section 1.1: Who is our audience?_"](https://third-bit.com/sdxjs/introduction/#introduction-audience) we can read that: > Like these three personas, readers should be able to: > [...] > • Install...