Design elements - ER diagram (Chen notation)

"Chen's notation for entity–relationship modeling uses rectangles to represent entity sets, and diamonds to represent relationships appropriate for first-class objects: they can have attributes and relationships of their own. If an entity set participates in a relationship set, they are connected with a line.
Attributes are drawn as ovals and are connected with a line to exactly one entity or relationship set.
Cardinality constraints are expressed as follows:
- a double line indicates a participation constraint, totality or surjectivity: all entities in the entity set must participate in at least one relationship in the relationship set;
- an arrow from entity set to relationship set indicates a key constraint, i.e. injectivity: each entity of the entity set can participate in at most one relationship in the relationship set;
- a thick line indicates both, i.e. bijectivity: each entity in the entity set is involved in exactly one relationship.
- an underlined name of an attribute indicates that it is a key: two different entities or relationships with this attribute always have different values for this attribute.
Attributes are often omitted as they can clutter up a diagram; other diagram techniques often list entity attributes within the rectangles drawn for entity sets." [Entity–relationship model. Wikipedia]
The vector stencils library ERD, Chen's notation contains 13 symbols for drawing entity-relatinship diagrams using the ConceptDraw PRO diagramming and vector drawing software.
The example "Design elements - ER diagram (Chen notation)" is included in the Entity-Relationship Diagram (ERD) solution from the Software Development area of ConceptDraw Solution Park.

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.