Consider the following premises. Joseph is a poet or Robert is climbing a mountain. If Robert climbs a mountain, then Michael is a mechanic. If Joseph were a poet, then Michael is a mechanic. It is late if and only if Michael is a mechanic. Sarah is taking a plane. Can we infer the following from them? Sarah is taking a plane and it is late.
 From the fact that if Joseph were a poet, then Michael is a mechanic, that if Robert climbs a mountain, then Michael is a mechanic, and that Joseph is a poet or Robert is climbing a mountain we can infer that Michael is a mechanic. From the fact that it is late if and only if Michael is a mechanic we can infer that if Michael were a mechanic, then it is late. From the fact that if Michael were a mechanic, then it is late, and that Michael is a mechanic we can infer that it is late. Finally, from the fact that Sarah is taking a plane, and that it is late we can infer that Sarah is taking a plane and it is late. Therefore, the answer is yes.