| a⬇︎b➡︎ |
-1 |
0 |
1 |
| -1 |
T |
F |
T |
| 0 |
F |
T |
F |
| 1 |
T |
F |
T |
So (a,b) satisfying the rules are (-1,-1), (-1,1), (0,0), (1,-1), (1,1).
For example: a=1 and b=-1; a=1 satisfies (2) and b=-1 satisfies (1); both (1) and (2) need to be true so we have T and T=T (both true means whole is true).
Another way is to separately assess (1) and (2).
(-1,-1)➝(1)=T because b=-1 and (2)=T because a=-1; T and T=T
(-1,0)➝(1)=F and (2)=F because a=-1 and b=0 so F and F=F
(-1,1)➝(1)=T because b=1 and (2)=T because a=-1 so T and T=T
(0,-1)➝(1)=F because a=0 and b=-1, and (2)=F so F and F=F
(0,0)➝(1)=T because a=0 and (2)=T because b=0, so T and T=T
(0,-1)➝(1)=F, because a=0 and b=-1, and (2)=F, so F and F=F
(1,-1)➝(1)=T because b=-1 and (2)=T because a=1 so T and T=T
(1,0)➝(1)=F and (2)=F because a=1 and b=0, so F and F=F
(1,1)➝(1)=T because b=1 and (2)=T because a=1, so T and T=T