What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Robert were a sailor, then it is overcast. Mary is not a taxi driver. If it is overcast, then Robert is a sailor. For all x_17, if x_17 were curious, then x_17 is a taxi driver. If it is overcast, then Mary is curious.
If Robert were a sailor, then Mary is curious. Robert is a sailor if and only if it is overcast. It is overcast if and only if Robert is a sailor.