SNOMED CT® Release Format 1 (RF1) Guide - ihtsdo

32 | SNOMED CT Release Format 1 (RF1) Guide July 2012
Concept
F
G
H
J
K
L
M
Transitive closure of supertypes
A, C
A, B, C, D
A, B, C, D, E
A, C, E, F
A, C, F
A, B, C, D, E, G, H
A, B, C, D, E, F, H, J
The advantage of this type of view is that there is no need to walk the hierarchy tree to answer the question
"is concept M subsumed by concept B". Instead this can be answered simply by checking the transitive closure
of " concept M" for the presence of " concept B". Therefore, this view enables high-performance subsumption
testing.
Note: Experience suggests that a pre-computed transitive closure table out-performs other options and
is robust, flexible and easy to implement. Therefore, unless storage capacity is significant concern, this
approach is recommended.
2.2.1.3.2.3.1.2. Proximal supertype view (standard distribution view)
An inferred view of a concept definition may contain relationships to the set of proximate supertype parents
of that concept. Relationships with other supertype ancestors that can be reached by traversing multiple | is
a | relationships are omitted.
© 2002-2012 International Health Terminology Standards Development Organisation CVR #: 30363434