# Equivalence of formulae

If I have two statement, say A and B. From which, I formed two formulae:

F1: (not A) and (not B)

F2: (not A) or (not B)

Do F1 and F2 entail each other? In other words, are they equivalent?

• "Do F1 and F2 entail each other?" by this do you mean that whether (a |= b) and (b |= a) ? – kiner_shah Jan 28 '17 at 13:37
• @kiner_shah Yes. I meant that. F1 |= F2 and vice-versa. – Coder Jan 28 '17 at 20:28
• That means you want to prove that whether the two statements are equivalent – kiner_shah Jan 29 '17 at 6:11