What can be inferred from the following premises in a single inference step (ignoring inferences that add new predicates or constants)? If Karen were a scientist, then Elisabeth is a lawyer. Elisabeth is a lawyer or Sarah is writing a letter. If Elisabeth were a lawyer, then Karen is a scientist. If Sarah writes a letter, then Karen is a scientist.
If Sarah writes a letter, then Elisabeth is a lawyer. Karen is a scientist. Karen is a scientist if and only if Elisabeth is a lawyer. Elisabeth is a lawyer if and only if Karen is a scientist.