Consider the following premises. If David were a carpenter, then Karen is writing a letter. If Elisabeth were a janitor, then Karen is writing a letter. David is a carpenter or William is climbing a mountain. If it is late, then Karen is not writing a letter. If William climbs a mountain, then Elisabeth is a janitor. Can we infer the following from them? If we can, name the inference rule being used: It is sunny.
We cannot infer that from the premises. Therefore the answer is no.