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 not poor. Barbara is playing a game if and only if Karen is sad. For all z_3, z_3 will play a game if and only if z_3 is poor.
If Barbara plays a game, then Karen is sad can be inferred via the biconditional elimination rule. If Karen were sad, then Barbara is playing a game can be inferred via the biconditional elimination rule. For all z_3, if z_3 plays a game, then z_3 is poor can be inferred via the universal biconditional elimination rule. For all z_3, if z_3 were poor, then z_3 is playing a game can be inferred via the universal biconditional elimination rule. For all z_3, z_3 will not play a game can be inferred via the universal biconditional elimination rule.