Question

Consider the argument: Attached
IS IT VALID OR INVALID?????????????????

Answer 1

Answer: Invalid

Step-by-step explanation:

The conclusion should be
`p \to r` due to the hypothetical syllogism rule (similar to the transitive rule).

You can make a truth table to show that the premises
`p \to q` and
`q \to r` can both be true at the same time, but the conclusion
`p \leftrightarrow q` is false. Whenever you have all true premises and a false conclusion, then the argument is invalid. True premises must lead to a true conclusion.