(uncountable) The condition of being nontrivial / (countable) Something notrivial

(mathematics) Not obvious or easy to prove; not self-evident. / (mathematics) Not being of the simplest kind; not being empty or a singleton.

In a nontrivial manner

plural of nontriviality

(logic) The rule that states that not all propositions are true, the opposite of trivialism.

plural of nontrivial solution

(linear algebra) any other answers apart from ⃑x=⃑0 to the linear system A⃑x=⃑0, signifying linear dependence of the linear system