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_7 for which x_7 is a writer. For all x_7, x_7 will play tennis or x_7 will work. For all x_7, if x_7 plays tennis, then x_7 is a mechanic. For all x_7, x_7 is not a mechanic.
For all x_7, x_7 will not play tennis.