What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? John is not an electrician. If it is cold, then Charles is curious. Charles is curious if and only if John is an electrician. It is overcast.
John is not an electrician and it is overcast. It is overcast and John is not an electrician. If Charles were curious, then John is an electrician. If John were an electrician, then Charles is curious. Charles is not curious.