A	B	C	D	Z
0	0	0	0	0
1	0	0	0	1
1	1	0	0	1
0	1	0	0	1
0	1	1	0	1
1	1	1	0	1
1	0	1	0	1
0	0	1	0	1
0	0	1	1	1
1	0	1	1	1
1	1	1	1	1
0	1	1	1	1
0	1	0	1	1
1	1	0	1	1
1	0	0	1	1
0	0	0	1	1

function: Z = !(!A && !B && !C && !D)