Adjective
Not trivial.
(mathematics) Not obvious or easy to prove; not self-evident.
(mathematics) Not being of the simplest kind; not being empty or a singleton.
nontrivial subgroup ― a subgroup with more than one element
(computing) Needing significant computing power to solve; intractable.
Source: en.wiktionary.orgAdditive groups of rings The additive group of a ring is an abelian group, but not all abelian groups are additive groups of rings (with nontrivial multiplication). Source: Internet
Although these theories appeared, at first, to be very different, work by several physicists showed that the theories were related in intricate and nontrivial ways. Source: Internet
An analogue of Rice's theorem for recursive sets One can regard Rice's theorem as asserting the impossibility of effectively deciding for any recursively enumerable set whether it has a certain nontrivial property. Source: Internet
Becker, Becker, and Schwarz 2007, pp. 339–347 Theories that arise as different limits of M-theory turn out to be related in highly nontrivial ways. Source: Internet
Blue arrows indicate T-duality main One notable fact about string theory is that the different versions of the theory all turn out to be related in highly nontrivial ways. Source: Internet
A zero divisor that is nonzero is called a nonzero zero divisor or a nontrivial zero divisor. Source: Internet