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: Karen is taking a plane if and only if David is running. David is running or it is not cold.
If it is cold, then David is running can be inferred via the rewriting rule. If Karen takes a plane, then David is running can be inferred via the biconditional elimination rule. If David goes running, then Karen is taking a plane can be inferred via the biconditional elimination rule.