Definition:Initial Segment/Also defined as

Initial Segment: Also defined as
Some sources use the term initial segment to refer to sets with a certain property a relation.

Terminology for such sets is currently not fixed on.

It is also worth noting that the concept of defining the set of all elements which are related to another element crops up throughout the fields of mapping theory and relation theory.

However, defining that set as a segment is usually done only in the context of order theory.