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: Jennifer is making tea and David is a server. For all x_16, x_16 will write a letter if and only if x_16 will make tea.
Jennifer is making tea can be inferred via the simplification rule. David is a server can be inferred via the simplification rule. For all x_16, if x_16 writes a letter, then x_16 is making tea can be inferred via the universal biconditional elimination rule. For all x_16, if x_16 makes tea, then x_16 is writing a letter can be inferred via the universal biconditional elimination rule.