A mathematical function is a relationship that is established between two sets, through which each element of the first set is assigned a single element of the second set or none at all. The initial set or starting set is also called the domain; the final set or arrival set is called range.
The common way to denote a function f is:
f: A--->B
a---->f(a)
{(0,0.2),(1,0.1),(1,1),(3,2)}
D: {0, 1, 3}
R: {0.2, 0.1, 1, 2}
This is not a function because:
(1, 0.1) and (1, 1)
