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Note
title Important Note
The examples on this page are illustrative only. Practical requirements and benefits of representing property transitivity and chains have been established. However, the concept model rules for applying these have not yet been finalized. Therefore, one of the two examples below refers to two concepts that do not currently exist in SNOMED CT and in the other example, it is likely that transitivity will apply to a specific subtype of the general |part of| attribute shown in the example.

Property Characteristics

If particular characteristics of the 

Gloss
t attributes

 used to define concepts are identified, this can enhance classification. For example, knowing that an attribute like 

Concept
t 123005000 |Part of|

 is transitive would allow the classifier to make infer that an entire finger is part of the entire upper limb.

Property Chains

Property chains are in some ways similar to transitivity but involve more than one attribute. For example,

Concept
t 127489000 |Has active ingredient|

 could be declared to chain with

Concept
t 738774007 |Is modification of|

. In that case, suppose the definition of 

Concept
t 387307005 |Calcium carbonate|

includes

Concept
t 738774007 |Is modification of|

 of

Concept
t 5540006 |Calcium|

, a DL classifier can determine that a tablet that

Concept
t 127489000 |Has active ingredient|

 = 

Concept
t 387307005 |Calcium carbonate|

 by definition has a modification of

Concept
t 5540006 |Calcium|

 as its active ingredient. Thus in the example shown the classifier can determine that 

Concept
ShowParts term t |calcium carbonate tablet|

 is a subtype of

Concept
ShowParts term t |calcium tablet|

.

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