Reputation: 29
I have a school assignment that needs to translate the English sentence into predicate logic.
The question is "Every fruit that is an apple is not a mango."
The domain is the whole world, and M(x) means x is a mango, A(x) means x is an apple, F(x) means x is a fruit.
The answer I came up with is "(∀x)[F(x)∧(A(x)⟶[M(x)]′)] " But there is someone who answers it like below.
"(∀x)[F(x)⟶(A(x)⟶[M(x)]′)]"
Will the second answer be a valid translation for the sentence "Every fruit that is an apple is not a mango."?
Upvotes: 1
Views: 346
Reputation: 30525
Both are correct. You're essentially asking if:
A -> (B -> C)
is equivalent to:
(A /\ B) -> C
And if you tabulate the truth tables, you'll see that these two propositions are always equivalent.
Upvotes: 1