It's not Julia's dynamic typing, but Julia's multimethod approach. For each function you don't have one set of arguments that must be generic enough to cover al

It's not Julia's dynamic typing, but Julia's multimethod approach. For each function you don't have one set of arguments that must be generic enough to cover all cases (for example f(number, number)), but you have one visible implementation for each combination of types (f(integer, complex), f(complex, integer), f(T, T) where T <: Number...) which makes it easier to know what the function actually covers. And the REPL (and editors plugins) has some good tools for searching for available methods, documentation and source code. Though while Julia has even sum and product types, it's not common for people to go to the level of detail of an ML language (plus you can't dispatch on the values of a struct), and there is no formal way to annotate an implicit interface for now, so each method will usually not be as clear from types alone as Ocaml.