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 curious if and only if z_3 is a sailor. For all z_3, z_3 is a sailor if and only if z_3 is curious.
For all z_3, if z_3 were curious, then z_3 is a sailor can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 were a sailor, then z_3 is curious can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 were a sailor, then z_3 is curious can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 were curious, then z_3 is a sailor can be inferred via the universal biconditional elimination rule.