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_7, if x_7 were a mechanic, then x_7 is running. There is at least one x_7 for which x_7 is a mechanic if and only if x_7 will go running.
There is at least one x_7 for which if x_7 were a mechanic, then x_7 is running can be inferred via the existential biconditional elimination rule. There is at least one x_7 for which if x_7 goes running, then x_7 is a mechanic can be inferred via the existential biconditional elimination rule.