"Books about architectural works, unless they are not intended for a general audience, . . . "
We are given a general principle here that applies to (1) "books about architectural works" that (2) are "intended for a general audience":
BAW & IFGA ==>
" . . . ought to include discussions of both the utility and the aesthetic appeal of each of the buildings they consider. If they do not, they are flawed."
So if either is missing, the work is flawed:
not U or not AA ==> F
But remember, this general principle only applies to "books about architectural works . . . intended for a general audience" so these requirements must also be present in our sufficient condition as follows:
