Given that  B(x) means “x is a bat”,  F(x) means “x is a fly”, and 

Given that 
B(x) means “x is a bat”, 
F(x) means “x is a fly”, and 
E(x, y) means “x eats y”,
what is the best English translation of ∀x(F(x) → ∀y(E(y, x) → B(y)))?

 

(A) all flies eat bats
(B) only bats eat flies
(C) every fly is eaten by some bat
(D)  every bat eats flies

Answer: B

In the given statement : ∀x(F(x) → ∀y(E(y, x) → B(y)))
∀y(E(y, x) → B(y)) means every bat eats some x
∀x(F(x) → ∀y(E(y, x) → B(y))) means every fly implies it is eaten by every bat 
in general all flies are eaten by bat only.

 

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