subset

IPA: sˈʌbsɛt

(set theory, of a set S) A set A such that every element of A is also an element of S.
A group of things or people, all of which are in a specified larger group.

(transitive) To take a subset of.
(transitive, computing, typography) To extract only the portions of (a font) that are needed to display a particular document.

Examples of "subset" in Sentences

Each subset is strictly contained within its superset.
This forms an ordered set such that each subset is strictly contained within its superset.
What would you call an arrangement such that each subset is strictly contained within its superset?
Each subset is strictly contained within its superset, hence is meets the definition of a nested hierarchy to which you agree above.
Yeah, I'm not sure how high parental involvement is ever going to be outside of a certain subset of small upper-middle-class schools.
You can call it what you want, but an ordered set such that each subset is contained within its superset is called a nested hierarchy.
In order for thenre to be an ordered set such that each subset is contained within its superset, all members must share the same defining characteristics.
Re: my use of spanish phrases, it pisses off a certain subset of conservatives, just like my "People Eating Tasty Animals" hat pisses off a certain subset of liberals.
Indeed, the bigger point to be made is that empiricism is all that we have to explain anything that we wish to understand, “physics” being only what we call a subset of empirically-based theories.