nonlinear
= N =
not entirely unlike X
nontrivial adj.
Requiring real thought or significant
computing power. Often used as an understated way of saying that a
problem is quite difficult or impractical, or even entirely
unsolvable ("Proving P=NP is nontrivial"). The preferred
emphatic form is `decidedly nontrivial'. See trivial,
uninteresting, interesting.
--The Jargon File version 4.3.1, ed. ESR, autonoded by rescdsk.