COMPUTER SECURITY AND PRIVACY

$(1)$ The question arises as to whether it is possible to develop a program that can analyze a

piece of software to determine if it is a virus. Consider that we have a program $D$ that is

supposed to be able to do that. That is$,$ for any program $P,$ if we run $D(P),$ the result

returned is TRUE $(P$ is a virus$)$ or FALSE $(P$ is not a virus$).$ Now consider the following

program: