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: Linda is not working. For all z, if z were a writer, then z is working. For all z, if z works, then z is a writer.
For all z, z is a writer if and only if z will work can be inferred via the universal biconditional introduction rule. For all z, z will work if and only if z is a writer can be inferred via the universal biconditional introduction rule.