Quote:
Originally Posted by pouramini
The book says
How a point in Z can be not a valid transform of any x?
I suppose any x will be mapped to a z! not!?

Here is my understanding:
Any
should be mapped to a
, but not any
can be mapped to a
: In other words, nonlinear transform
may not be an onto function.
For example the nonlinear transform
(given in the book), if
or
then there is no
can be mapped to such
because there is no
such that
and no
such that
.
Hope this helps.