UML Sequence Diagram. Design Elements

The vector stencils library "UML timing diagrams" contains 15 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"The following nodes and edges are typically drawn in a UML timing diagram: lifeline, state or condition timeline, destruction event, duration constraint, time constraint. ...
Lifeline is a named element which represents an individual participant in the interaction. ... lifelines represent only one interacting entity. ...
Lifeline on the timing diagrams is represented by the name of classifier or the instance it represents. It could be placed inside diagram frame or a "swimlane". ...
Timing diagram could show states of the participating classifier or attribute, or some testable conditions, such as a discrete or enumerable value of an attribute. ...
UML also allows the state/ condition dimension be continuous. It could be used in scenarios where entities undergo continuous state changes, such as temperature or density. ...
Destruction occurrence is a message occurrence which represents the destruction of the instance described by the lifeline. It may result in the subsequent destruction of other objects that this object owns by composition. No other occurrence may appear after the destruction event on a given lifeline.
Complete UML name of the occurrence is destruction occurrence specification. Until UML 2.4 it was called destruction event, and earlier - stop.
The destruction event is depicted by a cross in the form of an X at the end of a timeline. ...
Duration constraint is an interval constraint that refers to a duration interval. The duration interval is duration used to determine whether the constraint is satisfied.
The semantics of a duration constraint is inherited from constraints. If constraints are violated, traces become negative which means that system is considered as failed.
Duration constraint is shown as some graphical association between a duration interval and the constructs that it constrains. ...
Time constraint is an interval constraint that refers to a time interval. The time interval is time expression used to determine whether the constraint is satisfied.
The semantics of a time constraint is inherited from constraints. All traces where the constraints are violated are negative traces, i.e., if they occur, the system is considered as failed.
Time constraint is shown as graphical association between a time interval and the construct that it constrains. Typically this graphical association is a small line, e.g., between an occurrence specification and a time interval." [uml-diagrams.org/ timing-diagrams.html]
The example "Design elements - UML timing diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.

The vector stencils library "UML sequence diagrams" contains 50 symbols for the ConceptDraw PRO diagramming and vector drawing software.
"Sequence diagram ... building blocks.
If the lifeline is that of an object, it demonstrates a role. Note that leaving the instance name blank can represent anonymous and unnamed instances.
Messages, written with horizontal arrows with the message name written above them, display interaction. Solid arrow heads represent synchronous calls, open arrow heads represent asynchronous messages, and dashed lines represent reply messages. If a caller sends a synchronous message, it must wait until the message is done, such as invoking a subroutine. If a caller sends an asynchronous message, it can continue processing and doesn’t have to wait for a response. Asynchronous calls are present in multithreaded applications and in message-oriented middleware. Activation boxes, or method-call boxes, are opaque rectangles drawn on top of lifelines to represent that processes are being performed in response to the message (ExecutionSpecifications in UML).
Objects calling methods on themselves use messages and add new activation boxes on top of any others to indicate a further level of processing.
When an object is destroyed (removed from memory), an X is drawn on top of the lifeline, and the dashed line ceases to be drawn below it (this is not the case in the first example though). It should be the result of a message, either from the object itself, or another.
A message sent from outside the diagram can be represented by a message originating from a filled-in circle (found message in UML) or from a border of the sequence diagram (gate in UML)." [Sequence diagram. Wikipedia]
The example "Design elements - UML sequence diagrams" is included in the Rapid UML solution from the Software Development area of ConceptDraw Solution Park.