This is what I have so far.
let Swap (left : int , right : int ) = (right, left) let mutable x = 5 let mutable y = 10 let (newX, newY) = Swap(x, y) //<--thi
You can't; there's no syntax to update 'more than one mutable variable' with a single assignment. Of course you can do
let newX, newY = Swap(x,y) x <- newX y <- newY