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: It is snowing if and only if William is rich. William is rich if and only if Patricia is excited. For all y, y is not excited.
If it snows, then William is rich can be inferred via the biconditional elimination rule. If William were rich, then Patricia is excited can be inferred via the biconditional elimination rule. If William were rich, then it is snowing can be inferred via the biconditional elimination rule. If Patricia were excited, then William is rich can be inferred via the biconditional elimination rule.