If I understand it right "*/" results in a function that applies "*" between its arguments. "~" takes the function f(x) on its left and the argument y on its right and turns it into f(y, y).
So the right side of the tilde evaluates to a range 1..10. I think the tilde then turns its left and right into "*/"(1..10, 1..10), resulting in 1..10 * 1..10
