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_7, x_7 is a politician or x_7 will make tea. For all x_7, x_7 is not fast. For all x_7, x_7 will climb a mountain. For all x_7, x_7 is fast if and only if x_7 is a politician.
For all x_7, if x_7 were fast, then x_7 is a politician can be inferred via the universal biconditional elimination rule. For all x_7, if x_7 were a politician, then x_7 is fast can be inferred via the universal biconditional elimination rule. For all x_7, x_7 is not a politician can be inferred via the universal biconditional elimination rule.