What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_13, if x_13 were a politician, then x_13 is a mechanic. Karen is rich if and only if John is a politician. For all x_13, if x_13 were a mechanic, then x_13 is a politician. Karen is not rich.
If Karen were rich, then John is a politician. If John were a politician, then Karen is rich. John is not a politician. For all x_13, x_13 is a politician if and only if x_13 is a mechanic. For all x_13, x_13 is a mechanic if and only if x_13 is a politician.