Thread: Logic problems

Recall that -A \/ B is equivalent to A -> B and try rewriting the formulas you are given using this equivalence as much as possible.

for task a)
A = 1, B = 1, C = 1

LEFT: 1 -> (1 -> 1) gives 1 -> 1 gives 1

RIGHT: 0 ^ (0 v 1) gives 0 ^ 1 gives 0

1 =| 0 must be incorrect/false?

do you not have any proof methods e.g semantic tableau that you can use?

for task a)
A = 1, B = 1, C = 1

LEFT: 1 -> (1 -> 1) gives 1 -> 1 gives 1

RIGHT: 0 ^ (0 v 1) gives 0 ^ 1 gives 0

1 |= 0 must be incorrect/false?

Yes.

can we not just simply draw up three tableau's for these to show if they are true or if not find a model using the tableau?