What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If it is overcast, then it is snowing. If it snows, then Patricia is playing squash. If Patricia plays squash, then it is raining. If it rains, then it is overcast.
If it is overcast, then Patricia is playing squash. If it snows, then it is raining. If Patricia plays squash, then it is overcast. If it rains, then it is snowing.