A class that can't have any instances .
A dependency within which the client is at one level of abstraction and the supplier is at a different level.
An action that represents the receipt of a synchronous call request for an operation specified by a particular call trigger .
An action that waits for the occurrence of a signal of the type, or any subtype of that type, specified by a particular signal trigger .
An action that waits for an occurrence of a time event that meets the criteria specified by a particular time trigger .
A dependency within which the source package adds model elements that have private visibility from the target package.
An executable atomic assignment or computation that receives a set of input values and produces a change of state and/or the return of output values.
A class that represents an independent flow of control, such as a process or a thread.
An instance of an active class .
An ongoing nonatomic (in other words, interruptible) execution of a series of actions .
A diagram that illustrates the flow(s) of control among activities and actions associated with a particular object or set of objects.
A connection between activity nodes .
A final node that terminates all flows within a given activity , and thus terminates the activity itself.
A grouping of activity nodes and activity edges .
A placeholder for one or more steps within an activity .
A special type of activity node that appears at the beginning or end of a flow to accept inputs to an activity from another activity or to provide outputs from the activity to another activity.
An activity group that identifies actions that have some characteristics in common.
A role that a
An action that adds one or more values, specified on a particular input pin , to a specified structural feature.
An action that adds one or more values, specified on a particular input pin , to a given variable .
A piece of information that enhances an association .
A special kind of association within which one or more "part" classes belong to a larger "whole" class.
An action that applies a specified primitive function to a set of values that the action retrieves from a specified input pin , and then places the return values on a specified output pin .
A physical piece of information, such as a model, a file, or a table, used or produced by a software development process.
A connector that connects a required interface or a port on one component to a provided interface or port on another component.
A simple structural connection between classes .
An association that has interesting characteristics of its own outside of the classes it connects.
A named slot for a data value that belongs to a particular class .