Higher-kinded bounded polymorphism in OCaml (2021)

&gt; Thus, with type aliases, the type equality problem becomes the higher-order unification problem, which is not decidable.<p>I wonder how much this is a problem in practice, aside from the type-checker taking too long.

I&#x27;m more familiar with F#, so I got stuck at this line:<p><pre><code> type (&#x27;a,&#x27;b) app += List_name : &#x27;a list -&gt; (&#x27;a,list_name) app </code></pre> I understand that app is an extensible type and this line adds a union case called List_name to the type, but the signature of List_name confuses me. If I write (List_name x) is x a list or a function?

This article is pure gold. Rarely is this stuff explained so well.