Ok the question is:
Give an example of a function from N to N that is
(a) one-to-one but not onto
(b) onto but not one-to-one
(c) both onto and one-to-one
(d) neither one-to-one nor onto
(a) My answer is the function from {a,b,c} to {1,2,3,4} with f(a) = 2, f(b) = 3, f(c) = 1. Is this the correct example to this question?
What does it mean from N to N?
I kind of lost on how to show these examples. Thanks for any help!