all three are isomorphic. but in some languages if you define a function via something like `function myFun(x: Int, y: Bool) = ...` and also have some value `let a: (Int, Bool) = (1, true)` it doesn't mean you can call `myFun(a)`. because a parameter list is treated by the language as a different kind of construct than a tuple.

A language which truly treats an argument list as a tuple can support this:

    args = (a, b, c)
    f args

…and that will have the effect of binding a, b, and c as arguments in the called function.

In fact many “scripting” languages, like Javascript and Python, support something close to this using their array type. If you squint, you can see them as languages whose functions take a single argument that is equivalent to an array. At an internal implementation level this equivalence can be messy, though.

Lower level languages like C and Rust tend not to support this.