GO Classes 2023 | Weekly Quiz 5 | Question: 10

Let $\alpha, \beta$ be two propositional formulas.

Then which of the following is/are false?

1. If $(\neg \alpha \vee \beta)$ is valid, then $\alpha \models \beta$.
2. If $(\neg \alpha \vee \beta)$ is valid, then $\neg \alpha \models \beta$.
3. If $(\neg \alpha \vee \beta)$ is valid, then $\alpha \models \neg \beta$.
4. If $(\neg \alpha \vee \beta)$ is valid, then $\neg \beta \models \neg \alpha$.