> A more ambitious example: imagine the web with JavaScript replaced by Haskell. Your code compiles and typechecks in your browser, but that doesn't guarantee t

> A more ambitious example: imagine the web with JavaScript replaced by Haskell. Your code compiles and typechecks in your browser, but that doesn't guarantee that it will do the same in mine, or a different version of yours, or tomorrow's new browser. So these static type guarantees are very weak because they only apply to a single runtime environment. Wait... What? Are you saying that natural numbers in South America in 1990 century is different from natural numbers in Europe 2010? So how can types be different depending on browsers? Of course, if the browser implements a "compiler" that doesn't follow the basic principles reported in the standard of the language, it'll happen. If some joker wants to call `Int` a `String`, problems will happen. Otherwise, it is not true.