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: Barbara is running if and only if it is overcast. Barbara is running or Karen is a police officer. It is not overcast.
If Barbara goes running, then it is overcast can be inferred via the biconditional elimination rule. If it is overcast, then Barbara is running can be inferred via the biconditional elimination rule. Barbara is not running can be inferred via the biconditional elimination rule.