ABSTRACT
Now attention is turned to the formation of two new functions from a given function, called the image and preimage functions. First we define the image of a set under a function.
DEFINITION: If f : A —> B and S C A, i.e., S E P(A), then the image of the set S under L, denoted f [S] is given by
f[S] = If (s) 1 s E Sl. A particular example of the image of a set in the case where f C N x N
is treated in Example 16.1.
