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