New thread. Anyway, putting lisp/SLIME aside, I experimented with emacs lisp -- and got the same results, i.e., no real LOB functionality, despite proper loading. I must be doing something wrong? I'll describe my process again:

Load a.org and b.org into `org-babel-library-of-babel` with `org-babel-lob-ingest`. Good. Check -- and yes, both functions are in `org-babel-library-of-babel` and seem to be ready and "live." But when I try to call them in c.org, org-mode has no knowledge of them. Then I try #+call and #+lob on a b.org function. Still no knowledge of it. At this point I'm not sure LOB works -- or I have a mistaken idea of what it is and what it does.