What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Jessica were a mechanic, then it is cold. If Jessica were a mechanic, then it is overcast. If it is cold, then Jessica is a mechanic.
If it is cold, then it is overcast. Jessica is a mechanic if and only if it is cold. It is cold if and only if Jessica is a mechanic.