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: William is working if and only if it is cloudy. For all x_10, x_10 will not make tea. If it is cloudy, then Patricia is making tea.
If William works, then it is cloudy can be inferred via the biconditional elimination rule. If it is cloudy, then William is working can be inferred via the biconditional elimination rule.