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, x_8 will read a book if and only if x_8 will write a letter. For all x_8, x_8 is bored if and only if x_8 is a server. For all x_8, x_8 is bored if and only if x_8 will read a book. For all x_8, x_8 is not a server.
For all x_8, if x_8 reads a book, then x_8 is writing a letter can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 were bored, then x_8 is a server can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 were bored, then x_8 is reading a book can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 writes a letter, then x_8 is reading a book can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 were a server, then x_8 is bored can be inferred via the universal biconditional elimination rule. For all x_8, if x_8 reads a book, then x_8 is bored can be inferred via the universal biconditional elimination rule. For all x_8, x_8 is not bored can be inferred via the universal biconditional elimination rule.