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_3, z_3 is a soldier if and only if z_3 will cook. For all z_3, z_3 is not an artist. For all z_3, if z_3 were an artist, then z_3 is cooking. For all z_3, if z_3 cooks, then z_3 is an artist.
For all z_3, z_3 will not cook can be inferred via the universal modus tollens rule. For all z_3, z_3 is an artist if and only if z_3 will cook can be inferred via the universal biconditional introduction rule. For all z_3, z_3 will cook if and only if z_3 is an artist can be inferred via the universal biconditional introduction rule. For all z_3, if z_3 were a soldier, then z_3 is cooking can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 cooks, then z_3 is a soldier can be inferred via the universal biconditional elimination rule.