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: John is reading a book or James is drinking water. For all z_1, z_1 will drink water if and only if z_1 is an electrician. If John reads a book, then James is an electrician.
If James were a politician, then John is reading a book can be inferred via the rewriting rule. For all z_1, if z_1 drinks water, then z_1 is an electrician can be inferred via the universal biconditional elimination rule. For all z_1, if z_1 were an electrician, then z_1 is drinking water can be inferred via the universal biconditional elimination rule.