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: For all x_8, if x_8 were a lawyer, then x_8 is cooking. For all x_8, if x_8 cooks, then x_8 is a lawyer. Sarah is cooking.
There is at least one x for which x will cook can be inferred via the existential generalization rule. For all x_8, x_8 is a lawyer if and only if x_8 will cook can be inferred via the universal biconditional introduction rule. For all x_8, x_8 will cook if and only if x_8 is a lawyer can be inferred via the universal biconditional introduction rule.