What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Susan is a mechanic. For all x_13, if x_13 were a bartender, then x_13 is a mechanic. If Susan were a mechanic, then Susan is taking a plane. For all x_13, if x_13 takes a plane, then x_13 is a bartender.
There is at least one x for which x is a mechanic. For all x_13, if x_13 takes a plane, then x_13 is a mechanic.