Consider the following premises. Mary is not climbing a mountain. If David were an artist, then Robert is sleeping. Mary is climbing a mountain if and only if David is an artist. If Robert sleeps, then Mary is climbing a mountain. Can we infer the following from them? Robert is sleeping.
 From the fact that Mary is climbing a mountain if and only if David is an artist we can infer that if Mary climbs a mountain, then David is an artist. From the fact that if Mary climbs a mountain, then David is an artist, and that if David were an artist, then Robert is sleeping we can infer that if Mary climbs a mountain, then Robert is sleeping. From the fact that if Robert sleeps, then Mary is climbing a mountain, and that if Mary climbs a mountain, then Robert is sleeping we can infer that Robert is sleeping if and only if Mary is climbing a mountain. Finally, from the fact that Robert is sleeping if and only if Mary is climbing a mountain, and that Mary is not climbing a mountain we can infer that Robert is not sleeping, which contradicts that Robert is sleeping. Therefore, the answer is no.