The ListOf, OneOf, and ExpressionOf keywords provide a very powerful concept that is used throughout the System Architect's metamodel. Each provides you with the ability to say that a property of a definition references another object type - either Diagrams, Symbols, or Definitions.
So you are enabled to say that a class contains a list of methods (ListOf command), or a message between two objects references a method in the calling object (OneOf command), or that a process expresses procedures performed on data (ExpressionOf). We will look at these three expressions in turn in the sections to follow.
Note As with any keyword specified in USRPROPS.TXT, the case of the ListOf, OneOf, or ExpressionOf keywords is unimportant. We use all capitals for all keywords throughout this manual, except in this section, since ListOf, OneOf, or ExpressionOf are more descriptive of these keywords than the `all capitals' versions, LISTOF, ONEOF, and EXPRESSIONOF.