What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? For all x_5, x_5 is sad or x_5 is not a mechanic. For all x_5, if x_5 climbs a mountain, then x_5 is a mechanic. For all x_5, if x_5 works, then x_5 is climbing a mountain.
For all x_5, if x_5 works, then x_5 is a mechanic. For all x_5, if x_5 were a mechanic, then x_5 is sad.