Not necessarily, you don’t need to know the answer, the fabulation might: * give an error * return the wrong result * not be internally consistent with

Not necessarily, you don’t need to know the answer, the fabulation might: * give an error * return the wrong result * not be internally consistent with the rest of the content * be logically impossible * be factually impossible * have basic errors It is entirely possible (and quite common) to know something is wrong without knowing what a right answer is.