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 z, z will work. For all z, z will work if and only if z will go running. There is at least one z for which z is a musician.
Some musicians will work can be inferred via the existential conjunction rule. There is at least one z for which z will work and z is a musician can be inferred via the existential conjunction rule. For all z, if z works, then z is running can be inferred via the universal biconditional elimination rule. For all z, if z goes running, then z is working can be inferred via the universal biconditional elimination rule.