A 
in which none of the referenced 
are 
and where there is no redundancy or duplication of meaning.
Notes
- In theory, an
can be transformed to its normal form by replacing each reference to a 
with a nested that represents the definition of that . However, this process often results in redundancy or duplication of meaning requiring removal of less specific 
and mergers of 
. Therefore, use of 
is more effective way to normalize and compare 
.
Change Notice
- Prior to the July 2019
, two normal form expressions could be compared to determine whether they were logically equivalent 
or whether one was 
by the other. The July 2019 release included enhancements to the 
used by 
. As a result of these enhancements, expression transformation is no longer a reliable option for 
. Instead, postcoordinated expressions should be classified using a to determine subsumption.
Related Links
- Description Logic Enhancements