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: Thomas is not a poet. Thomas is a poet if and only if Barbara is a server. If Thomas were a poet, then Barbara is a server. Elisabeth is making tea.
Thomas is not a poet and Elisabeth is making tea can be inferred via the conjunction rule. Elisabeth is making tea and Thomas is not a poet can be inferred via the conjunction rule. If Thomas were a poet, then Barbara is a server can be inferred via the biconditional elimination rule. If Barbara were a server, then Thomas is a poet can be inferred via the biconditional elimination rule. Barbara is not a server can be inferred via the biconditional elimination rule.