What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? It is overcast if and only if Patricia is climbing a mountain. Patricia is climbing a mountain if and only if Richard is a server. It is not late. Richard is a server if and only if it is late.
If it is overcast, then Patricia is climbing a mountain. If Patricia climbs a mountain, then Richard is a server. If Richard were a server, then it is late. If Patricia climbs a mountain, then it is overcast. If Richard were a server, then Patricia is climbing a mountain. If it is late, then Richard is a server. Richard is not a server.