01[0:0] = 1
01[1:0] = 01
01[1:1] = 0
101[0:0] = 1
101[1:0] = 01
101[2:0] = 101
101[1:1] = 0
101[2:1] = 10
101[2:2] = 1
11110000[7:4] = 1111
11110000[5:2] = 1100
11110000[3:0] = 0000