What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Elisabeth takes a plane, then Barbara is climbing a mountain. If Robert were an electrician, then Karen is writing a letter. If Barbara climbs a mountain, then Robert is an electrician. Elisabeth is taking a plane. If Susan were a cashier, then Karen is writing a letter.
Barbara is climbing a mountain. If Elisabeth takes a plane, then Robert is an electrician. If Barbara climbs a mountain, then Karen is writing a letter.