# KEHOME/knowledge/theory/KRdesign/dot.html
# May/13/2003

## Exploring the ... concept

### To facilitate the exploration of concept-hierarchies
(or concept-lattices), I have extended the UNIX directory
"dot" notation to three levels:

/ | is existent
.. | is the current genus of the current concept
. | is the current concept
... | is the current species|unit of the current concept

The three "dot" concepts can be used in any Knowledge Explorer
statement, command or question. The "next" concept
steps through all possible values of ".." or "...". The "dot"
concepts are especially handy when the concept names are long.
For example, consider the heading lattice from Keith Devlin's book
"Goodbye, Descartes" (KEHOME/knowledge/examples/BookHierarchy/gd.ho).
It is a lattice, not a hierarchy, because "Goodbye, Descartes" is
the heading for both the book (the title) and a chapter section.
If I hadn't included the chapter number, straight from the
table of contents, "Goodbye, Descartes" would also be the
heading of chapter 11.
After loading the lattice

do read from gd.ho done;

and making "Goodbye, Descartes" the current concept

do find od Goodbye* done;
set . = $Command;

successive applications of the next concept assignment

set ... = next;

give all the chapter headings, and

set .. = next;

gives the heading of chapter 11.
The Knowledge Explorer input prompt can have one of the three forms

<cview:..=cgenus>
<cview:.=cconcept>
<cview:...=cspecies>

depending on whether or not the "next" concept assignment is in progress.
The names are

cview | current view
cgenus | current genus of current concept
cconcept | current concept
cspecies | current species|unit of current concept

General References