# 1999/3/24

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# the genus of genus is attribute #
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The purpose of this note (KEHOME/define/genus.txt)
is to discuss the definition of genus,
in order to illustrate
	my "changes" to Ayn Rand's definition
	the use of KR

1. the KR language
KR is a highly structured, English-like language.
The purpose of KR is provide a thinking tool that
represents knowledge in computer-processable form.

2. genus-differentia definitions
KR expresses a genus-differential definition as
	C is G with D
where
C is the concept being defined
G is the genus of the concept - the wider concept that is
	one level higher in the entity-relation hierarchy
	of the context
D is the differentia of the concept - the characteristics
	which distinguish C from other concepts with the
	same genus G

The most basic characteristics are attribute and action.

3. Ayn Rand's definition of genus
genus is the wider class of existents
which share a conceptual common denominator(s)
with the existents subsumed by the concept being defined.

Using the quote mark for grouping, the literal KR
translation is
	genus is "the wider class of existents" with
	"share a conceptual common denominator(s) with the \
	existents subsumed by the concept being defined"

4. my definition of genus
"the wider class of existents" actually describes the value
of the genus of genus.  The genus of a concept is an attribute
of a concept.  A more correct definition is
	genus is attribute with
	"the wider class of existents which share a conceptual \
	common denominator(s) with the existents subsumed by the \
	concept being defined"

5. more convenient form
The correct definition, given in 4, is very awkward because of
the "extra" level of attribute.  That problem can be avoided
by simply acknowledging the extra level as follows:
	genus/value is "the wider class of existents" with
	"share a conceptual common denominator(s) with the \
	existents subsumed by the concept being defined"