3. Complex, but solvable by methods so well known that anyone not
utterly *cretinous* would have thought of them
already.

4. Any problem one has already solved (some claim that hackish
trivial usually evaluates to
“I've seen it before”). Hackers' notions of triviality may be
quite at variance with those of non-hackers. See
*nontrivial*,
*uninteresting*.

The physicist Richard Feynman, who had the hacker nature to an
amazing degree (see his essay “Los Alamos From Below” in
*Surely You're Joking, Mr. Feynman!*), defined
trivial theorem as “one that
has already been proved”.