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 make tea. There is at least one z for which z will not make tea. For all z, z is a scientist.
For all z, z will make tea and z is a scientist can be inferred via the universal conjunction rule. For all z, z is a scientist and z will make tea can be inferred via the universal conjunction rule.