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: There is at least one x_3 for which x_3 will make tea if and only if x_3 is a sailor. For all x_3, if x_3 makes tea, then x_3 is excited.
There is at least one x_3 for which if x_3 makes tea, then x_3 is a sailor can be inferred via the existential biconditional elimination rule. There is at least one x_3 for which if x_3 were a sailor, then x_3 is making tea can be inferred via the existential biconditional elimination rule.