j$.$ The system has four inputs, $a,b,c,$ and $d,$ and one output, $f.$

The last three inputs $(b,c,d)$ represent a binary number, $n,$ in

the range $0$ to $7$ ; however, the input $0$ never occurs. The first

input $($a$)$ specifies which of two computations is made.

$a=0$:$f$ is $1$ iff $n$ is a multiple of $2$

$a=1$:$f$ is $1$ iff $n$ is a multiple of $3$