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 x_8, if x_8 makes tea, then x_8 is a server. Robert is making tea if and only if Jennifer is excited. For all x_8, if x_8 were a server, then x_8 is making tea. Jennifer is not excited.
If Robert makes tea, then Jennifer is excited can be inferred via the biconditional elimination rule. If Jennifer were excited, then Robert is making tea can be inferred via the biconditional elimination rule. Robert is not making tea can be inferred via the biconditional elimination rule. For all x_8, x_8 will make tea if and only if x_8 is a server can be inferred via the universal biconditional introduction rule. For all x_8, x_8 is a server if and only if x_8 will make tea can be inferred via the universal biconditional introduction rule.