A function is merely a way of associating with each value of one set (the "domain") a value in another set.
f - name of the function
A function is merely a way of associating with each value of one set (the "domain") a value in another set.
f - name of the function
Say f(A) "returns" or "yields" this value.
Note that f is the name of the function, not the function itself.
One function can have many names.