Question

Is the relation `{(1, 3) (2, 4)}` a function?

Answer 1

Since `(x,y) = {(1,3),(2,4)}` provides a unique mapping for any value of `x` into a value of `y` (that is the values of `x` are not duplicated in the pairs of the set)
`color(white)("XXXX")`this is a function.