What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one z for which z will write a letter if and only if z is an electrician. For all z, z will not cook. For all z, z is an electrician if and only if z will drink water. For all z, z will cook if and only if z will drink water.
For all z, if z were an electrician, then z is drinking water. For all z, if z cooks, then z is drinking water. There is at least one z for which if z writes a letter, then z is an electrician. For all z, if z drinks water, then z is an electrician. For all z, if z drinks water, then z is cooking. There is at least one z for which if z were an electrician, then z is writing a letter. For all z, z will not drink water.