In: Advanced Math
Construct the truth-table for the following propositional formulas. In each case, explain whether the formula is a tautology, a contradiction, or neither. (Explain how you arrive at this conclusion.) (a) ¬((p → ¬p) → ¬p) (b) (p → (q ∧ r)) → (¬r → ¬p) (c) (p → ¬q) → ¬(¬p → q)
If the truth table gives only TRUE values then the proposition is called Tautology
If the truth table gives only FALSE values then the proposition is called Contradiction
If the truth table gives neither tautology nor contradiction then it is called as contingency
P |
Q |
¬p |
¬q |
p → ¬p |
(p → ¬p) → ¬p |
¬((p → ¬p) → ¬p) |
T |
T |
F |
F |
F |
T |
F |
T |
F |
F |
T |
F |
T |
F |
F |
T |
T |
F |
T |
T |
F |
F |
F |
T |
T |
T |
T |
F |
So this was a contradiction
P |
Q |
R |
¬p |
¬r |
(q ∧ r) |
(p → (q ∧ r)) |
(¬r → ¬p) |
(p → (q ∧ r)) → (¬r → ¬p) |
T |
T |
T |
F |
F |
T |
T |
T |
T |
T |
T |
F |
F |
T |
T |
T |
F |
F |
T |
F |
T |
F |
F |
T |
T |
T |
T |
T |
F |
F |
F |
T |
F |
F |
F |
T |
F |
T |
T |
T |
F |
T |
T |
T |
T |
F |
T |
F |
T |
T |
T |
T |
T |
T |
F |
F |
T |
T |
F |
T |
T |
T |
T |
F |
F |
F |
T |
T |
F |
T |
T |
T |
So this was a contingency
P |
Q |
¬p |
¬q |
p → ¬q |
¬p → q |
¬(¬p → q) |
(p → ¬q) → ¬(¬p → q) |
T |
T |
F |
F |
F |
T |
F |
T |
T |
F |
F |
T |
T |
T |
F |
F |
F |
T |
T |
F |
T |
F |
T |
T |
F |
F |
T |
T |
T |
F |
T |
T |
So this was a contingency