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_10, if x_10 were an artist, then x_10 is a lawyer. It is late if and only if Mary is a lawyer.
If it is late, then Mary is a lawyer can be inferred via the biconditional elimination rule. If Mary were a lawyer, then it is late can be inferred via the biconditional elimination rule.