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: If Barbara drinks water, then it is raining. Joseph is working if and only if Barbara is drinking water. Sarah is not running. Sarah is running if and only if it is raining.
If Joseph works, then Barbara is drinking water can be inferred via the biconditional elimination rule. If Sarah goes running, then it is raining can be inferred via the biconditional elimination rule. If Barbara drinks water, then Joseph is working can be inferred via the biconditional elimination rule. If it rains, then Sarah is running can be inferred via the biconditional elimination rule. It is not raining can be inferred via the biconditional elimination rule.