What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: Michael is working if and only if it is sunny. If it rains, then Michael is working. If it is sunny, then Elisabeth is reading a book. Susan is listening to a song or Elisabeth is not reading a book.
If Elisabeth reads a book, then Susan is listening to a song can be inferred via the rewriting rule. If Michael works, then it is sunny can be inferred via the biconditional elimination rule. If it is sunny, then Michael is working can be inferred via the biconditional elimination rule.