1. (∀x)[(Hx • x≠a) ⊃ Jax]
2. Hb • Ib • Mb • (∀x)[(Ix • Mx) ⊃ x=b]
3. Ha • ∼Ma
-Which of the following propositions is an immediate (one-step) consequence in F of the given premises?
A) ~Ma • Mb
B) (∀x)[(Ix • Mx) ⊃ x=b] • Mb
C) (Hb • b≠a) ⊃ Jab
D) Hb • Ib • Mb • [(Ia • Ma) ⊃ a=b]
E) (Ha • a≠a) ⊃ Jax

Question

Quizplus · Accepted Answer

From premise 1, we know that if something is H and not equal to a (i.e. it is not a), then it is J. Therefore, if b is H and not equal to a, then it is J. This is exactly what choice C says, so it is an immediate consequence of the premises. None of the other choices can be derived with just one step of logic.

1. (∀X)[(Hx • X≠a) ⊃ Jax]