Consider the following premises. If William were excited, then Elisabeth is playing squash. If Mary were a janitor, then William is excited. If Elisabeth plays squash, then Mary is a janitor. It is windy if and only if William is excited. It is not windy. Can we infer the following from them? Elisabeth is playing squash.
 From the fact that it is windy if and only if William is excited, and that it is not windy we can infer that William is not excited. From the fact that if Elisabeth plays squash, then Mary is a janitor, and that if Mary were a janitor, then William is excited we can infer that if Elisabeth plays squash, then William is excited. From the fact that if Elisabeth plays squash, then William is excited, and that if William were excited, then Elisabeth is playing squash we can infer that Elisabeth is playing squash if and only if William is excited. Finally, from the fact that Elisabeth is playing squash if and only if William is excited, and that William is not excited we can infer that Elisabeth is not playing squash, which contradicts that Elisabeth is playing squash. Therefore, the answer is no.