Help with excitation table pls

**broken link removed**

im having trouble understanding this, does Qn' equal to Qn+1? because assuming it does the values i get dont match up with the solution, could someone help explain it for me, for example when i took Qn - 0 and Qn' - 1 it would give me (0+B)'=0'*B'=1*B'=1 hence B'=1 B=0 which is wrong

Qn is the present state.
Qn+1 is the next state.

For example, the second row:

Qn = 0
Qn+1 = 1

Means:
"I have an output = 0, what does it need to make the output = 1 ?"

For example, the third row:

Qn = 1
Qn+1 = 0

Means:
"I have an output = 1, what does it need to make the output = 0 ?"