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_14, if x_14 were an astronaut, then x_14 is working. If it is overcast, then John is working. John is an astronaut or it is overcast. If John plays squash, then John is not working.
Nothing can be inferred from these premises.