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, x_10 will read a book or x_10 will sleep. For all x_10, if x_10 reads a book, then x_10 is playing a game. For all x_10, x_10 will not play a game. There is at least one x_10 for which x_10 will sleep if and only if x_10 is a lawyer.
For all x_10, x_10 will not read a book can be inferred via the universal modus tollens rule. There is at least one x_10 for which if x_10 sleeps, then x_10 is a lawyer can be inferred via the existential biconditional elimination rule. There is at least one x_10 for which if x_10 were a lawyer, then x_10 is sleeping can be inferred via the existential biconditional elimination rule.