Here are brief definitions of selected terms, pattern names, and other concepts used in the book.
AGGREGATE A cluster of associated objects that are treated as a unit for the purpose of data changes. External references are restricted to one member of the AGGREGATE, designated as the root. A set of consistency rules applies within the AGGREGATE’S boundaries.
analysis pattern A group of concepts that represents a common construction in business modeling. It may be relevant to only one domain or may span many domains (Fowler 1997, p. 8).
ASSERTION A statement of the correct state of a program at some point, independent of how it does it. Typically, an ASSERTION specifies the result of an operation or an invariant of a design element.