Answer:
The conclusion "T" logically follows from the premises given and the argument is valid
Step-by-step explanation:
Let us use notations to represent the steps
P: I take a bus
Q: I take the subway
R: I will be late for my appointment
S: I take a taxi
T: I will be broke
The given statement in symbolic form can be written as,
(P V Q) → R
S → (¬R ∧ T)
(¬Q ∧ ¬P) → S
¬R
___________________
∴ T
PROOF:
1. (¬Q ∧ ¬P) → S Premise
2. S → (¬R ∧ T) Premise
3. (¬Q ∧ ¬P) → (¬R ∧ T) (1), (2), Chain Rule
4. ¬(P ∨ Q) → (¬R ∧ T) (3), DeMorgan's law
5. (P ∨ Q) → R Premise
6. ¬R Premise
7. ¬(P ∨ Q) (5), (6), Modus Tollen's rule
8. ¬R ∧ T (4), (7), Modus Ponen's rule
9. T (8), Rule of Conjunction
Therefore the conclusion "T" logically follows from the given premises and the argument is valid.
