What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all z, if z were a carpenter, then z is making tea. There is at least one z for which if z makes tea, then z is a carpenter. For all z, z is not a carpenter.
There is at least one z for which z will not make tea. There is at least one z for which z will make tea if and only if z is a carpenter. There is at least one z for which z is a carpenter if and only if z will make tea.