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 William were curious, then it is late. Jennifer is working if and only if it is late. If it is late, then William is curious.
William is curious if and only if it is late can be inferred via the biconditional introduction rule. It is late if and only if William is curious can be inferred via the biconditional introduction rule. If Jennifer works, then it is late can be inferred via the biconditional elimination rule. If it is late, then Jennifer is working can be inferred via the biconditional elimination rule.