What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? Name the inference rule being used: For all x_17, x_17 will sleep or x_17 is a janitor. For all x_17, x_17 will not sleep. If Jennifer plays squash, then Barbara is not a taxi driver. For all x_17, x_17 is not a janitor.
Since the premises are contradictory, we can infer anything from them.