Consider the following premises. For all x_8, x_8 is a musician if and only if x_8 will climb a mountain. Karen is not climbing a mountain. Can we infer the following from them? Karen is a musician.
 From the fact that for all x_8, x_8 is a musician if and only if x_8 will climb a mountain we can infer that for all x_8, if x_8 were a musician, then x_8 is climbing a mountain. From the fact that for all x_8, if x_8 were a musician, then x_8 is climbing a mountain we can infer that if Karen were a musician, then Karen is climbing a mountain. Finally, from the fact that if Karen were a musician, then Karen is climbing a mountain, and that Karen is not climbing a mountain we can infer that Karen is not a musician, which contradicts that Karen is a musician. Therefore, the answer is no.