# Role of subtype Relationships

provide the main semantic that relates to one another.

All , except the root , have with one or more . Each of these indicates that a is a of another .

# Representation of Subtype Relationships

are expressed in the same way as all other . They are identifiable by their RelationshipType, which refers to a with the .

The has a designated , which is documented in this guide as an Important Concept Identifier.

# Subtype Relationships and the Subtype Hierarchy

represent the of . This is illustrated here using a small sample set of and listed in . [ 1

 `Subtype Relationships Example`

Source

Destination

Only the most proximate are represented in the distribution files. These are shown by the blue lines in . However, a is a of any to which it has a direct or indirect .

• Thus the is a of all the other shown in the diagram.

Example:

is a of because it is a of which is a of

GRAPHIC HERE

 `_0e7ff052-9e2f-4878-bbed-2dbd7523cbfb__9Figure 1. Graphical view of the of the Supertypes ofidINLINE53084003|Bacterial pneumonia (disorder)|`

The number of links in the chain of between two does not alter the logical meaning of the between them. The number of between two may change between releases of as a result of the addition of an intermediate . This does not alter the semantic between them.

Some technical implementation issues are affected by whether a pair of is linked by a single or by a sequence of several . In this guide, the following are used where this distinction is technically significant:

A given ( -x) may have:

• - with a referring to -x:
• is a of:
• \ - referred to by a from -x:
• is a of:
• - with that refer to other that are either or of -x:
• is a of:
• All other shown in the example.
• - referred to by from other that are either parent or of -x:
• is an of:
• All other shown in the example, except for .

 `I nverted hierarchical view of the Supertypes ofidINLINE53084003|Bacterial pneumonia (disorder)|`