In Haskell you use typeclasses (you can think of them as Go interfaces or Rust traits) and without them you cannot introduce nameclashes. In Scheme (the Lisp that I know)... you don't have anything. You import things from libraries, define variable bindings and depending on the order of all this your variable is going to be bound to something, most likely a procedure... but which one? Depends on the order. Not great. I prefer the Haskell approach to this, but then Haskell is a bit complicated in other areas. :/

But again, this has little to do with "operators vs functions".

It has to do with it in the sense that you can add package names or namespaces to function names which are already text, but it looks bad to do this with symbolic infix operators like "+"

It would be nice if everything that operates looks exactly the same, but maybe the field of mathematics could start with fixing their notation then instead: mathematics uses a bit of everything you can imagine:

add, subtract, multiply, division, power, root and log are all binary operators and instead of making them all look the same, mathematicians have chosen to:

* infix symbol for add and subtract

* no symbol at all (usually) for multiply

* superscript for power

* horizontal bar and put things on top of each other for division

* another horizontal bar and a superscript on the left for root

* function-name notation with subscript for log

Maybe this is a global optimum that math has converged to because this mix of different things actually is the easiest way for the human brain to read formulas the fastest, e.g. the arbitrary grouping that division creates and the fact that this eliminates the need for some parenthesis, and the easy visual difference between all the different notations, may really help. In some programming languages, if you've got dozens of parenthesis or deeply nested indentation, can you easily tell which argument is to which function?

Or, it's just a historically grown monster that could as well have turned out entirely different and can have other forms that would be faster to interpret.

At the point when there was an effort to formalize these things ideas like RPN starting popping up.

Mathematics also deals with a much more flexible medium. It's written on a plane, in 2 dimensions, whereas programmers confine themselves to just one. Mathematicians are also free to make up their own notation and symbols, whereas programmers are confined to a single alphabet and most often can't extend the syntax.

EDIT: Case in point: some mathematicians argued for a while if abs (absolute value) is a function. Some argued that it's not, because you need two formulas to define it. When somebody pointed out that (for real numbers) it's just "sqrt(x^2)", the first ones agreed. Sounds silly in retrospect now that we have a set-theoretic definition, but at the time it wasn't obvious and all these functions looked very different from each other.

Isn't that a circular definition, though? sqrt(x²) = ±x, which isn't a function since there are two values in the domain for each value in the range (other than zero). The version they're equating with abs(x) is the absolute value of the square root, or abs(x) = abs(sqrt(x²)), which is true but wouldn't help prove that abs(x) is a function.

Of course, the underlying problem was the premise that a function must be defined by exactly one formula.

Why not just say that abs(x) = ±x, ignoring the negative solutions? If you'll accept "the non-negative square root of x²" then I see no reason to reject "the non-negative component of ±x". Both are single formulas with positive and negative solutions combined with a qualifier rejecting the negative solutions.

When people write "sqrt", they mean the function, or, "principal square root". "A square root" is a different thing. Saying "the definition" makes sense only within the context where the definition is established, otherwise we have to fallback to the common usage. Wittgenstein would laugh at this conversation.

Also, I'm not arguing for this convention ("it needs to have a single formula to be a function"). And when you start substituting symbols, almost nothing withstands this test. Because then you can always always twist the formula into several cases. And generally thinking about functions as something that is defined by formulas is a very limiting view. Almost all functions cannot be defined by formulas.