The conclusion, this time, is false. Looking at the truth table, we see that there is no row in which the premises are true, but the conclusion is simultaneously false. We have seen a valid argument. How about an invalid one. If Homer is a Simpson, then Homer likes donuts.
Homer likes donuts.
Therefore, Homer is a Simpson. Yes, the third row illustrates such a case. Therefore, the argument is invalid. We may verify this finding by constructing a counterexample, as we did in Chapter 2. If lemons are red, then lemons have a color.