1. (∀x)[(Cx • Exa) ⊃ Dx]
2. Cd • ∼Dd
-Which of the following propositions is derivable from the given premises in F?
A) ∼Eda
B) ~(∃x)Exa
C) (∀x)Exa
D) Eda
E) Eaa

Question

Quizplus · Accepted Answer

From premise 2, we know that Cd is true and ∼Dd is true. From premise 1, we know that for any x that is both a C and an E of a, Dx is true. Since d is not a D, we can conclude that d is not an E of a, or ∼Eda is true.

1. (∀X)[(Cx • Exa) ⊃ Dx]