What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Karen climbs a mountain, then John is writing a letter. If it rains, then Karen is climbing a mountain. If Robert were a politician, then it is raining. If John writes a letter, then Robert is a politician.
If Karen climbs a mountain, then Robert is a politician. If it rains, then John is writing a letter. If Robert were a politician, then Karen is climbing a mountain. If John writes a letter, then it is raining.