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_12, x_12 will not listen to a song. For all x_12, if x_12 were a server, then x_12 is a poet. For all x_12, x_12 is a server if and only if x_12 will work. For all x_12, x_12 is a server if and only if x_12 is a poet. For all x_12, x_12 will listen to a song if and only if x_12 will work.
For all x_12, if x_12 were a server, then x_12 is working can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 were a server, then x_12 is a poet can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 listens to a song, then x_12 is working can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 works, then x_12 is a server can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 were a poet, then x_12 is a server can be inferred via the universal biconditional elimination rule. For all x_12, if x_12 works, then x_12 is listening to a song can be inferred via the universal biconditional elimination rule. For all x_12, x_12 will not work can be inferred via the universal biconditional elimination rule.