What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? There is at least one x_13 for which x_13 is a taxi driver if and only if x_13 is fast. For all x_13, if x_13 were bored, then x_13 is fast. For all x_13, x_13 is not a taxi driver. For all x_13, x_13 is bored or x_13 is happy.
There is at least one x_13 for which if x_13 were a taxi driver, then x_13 is fast. There is at least one x_13 for which if x_13 were fast, then x_13 is a taxi driver. There is at least one x_13 for which x_13 is not fast.