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: Patricia is excited if and only if it is snowing. If it snows, then Patricia is excited. It is snowing or Patricia is not excited.
If Patricia were excited, then it is snowing can be inferred via the rewriting rule. If Patricia were excited, then it is snowing can be inferred via the biconditional elimination rule. If it snows, then Patricia is excited can be inferred via the biconditional elimination rule.