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: For all x, if x works, then x is running. There is at least one x for which x will not go running. For all x, if x goes running, then x is working.
There is at least one x for which x will not work can be inferred via the existential modus tollens rule. For all x, x will work if and only if x will go running can be inferred via the universal biconditional introduction rule. For all x, x will go running if and only if x will work can be inferred via the universal biconditional introduction rule.