Consider the following premises. If it is sunny, then Mary is an artist. It is not sunny. William is bored. If Mary were an artist, then it is sunny. If Charles makes tea, then Mary is an artist. Can we infer the following from them? If we can, name the inference rule being used: Charles is making tea.
 From the fact that if Mary were an artist, then it is sunny, and that if it is sunny, then Mary is an artist we can infer that Mary is an artist if and only if it is sunny via biconditional introduction. From the fact that Mary is an artist if and only if it is sunny, and that it is not sunny we can infer that Mary is not an artist via biconditional elimination. Finally, from the fact that if Charles makes tea, then Mary is an artist, and that Mary is not an artist we can infer that Charles is not making tea via modus tollens, which contradicts that Charles is making tea. Therefore, the answer is no.