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: If James sleeps, then Mary is making tea. If Mary makes tea, then James is sleeping. It is not cold. It is cold if and only if Mary is making tea.
James is sleeping if and only if Mary is making tea can be inferred via the biconditional introduction rule. Mary is making tea if and only if James is sleeping can be inferred via the biconditional introduction rule. If it is cold, then Mary is making tea can be inferred via the biconditional elimination rule. If Mary makes tea, then it is cold can be inferred via the biconditional elimination rule. Mary is not making tea can be inferred via the biconditional elimination rule.