Conceptual graph
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- Cat-on-mat.GIF -
Elsie the cat is sitting on a mat
A
conceptual graph (CG) is a notation for logic based on the
existential graphs of
Charles Sanders Peirce and the
semantic networks of
artificial intelligence. In the first published paper on CGs,
John F. Sowa used them to represent the
conceptual schemas used in database systems. The first book on CGs (Sowa 1984) applied them to a wide range of topics in artificial intelligence, computer science, and cognitive science. A linear notation, called the
Conceptual Graph Interchange Format (CGIF), has been standardized in the ISO standard for
Common Logic.The diagram on the right is an example of the
display form for a conceptual graph. Each box is called a
concept node, and each oval is called a
relation node. In CGIF, this CG would be represented by the following statement:
[Cat Elsie] [Sitting *x] [Mat *y] (agent ?x Elsie) (location ?x ?y)
In CGIF, brackets enclose the information inside the concept nodes, and parentheses enclose the information inside the relation nodes. The letters x and y, which are called
coreference labels, show how the concept and relation nodes are connected. In the
Common Logic Interchange Format (CLIF), those letters are mapped to variables, as in the following statement:
(exists ((x Sitting) (y Mat)) (and (Cat Elsie) (agent x Elsie) (location x y)))
As this example shows, the asterisks on the coreference labels *x and *y in CGIF map to existentially quantified variables in CLIF, and the question marks on ?x and ?y map to bound variables in CLIF. A universal quantifier, represented
@every*z in CGIF, would be represented
forall (z) in CLIF.
See also
References
- Sowa, John F. (1984), Conceptual Structures: Information Processing in Mind and Machine, Addison-Wesley, Reading, MA, 1984.
- Sowa, John F. (1976), "Conceptual Graphs for a Data Base Interface", IBM Journal of Research and Development 20(4), 336–357, July 1976. PDF file.
External links
People
There is a lively worldwide conceptual graphs research community, which began with a series of seven annual workshops that met from 1986 to 1992. In 1993, the workshops were upgraded to the
International Conferences on Conceptual Structures (ICCS), which have been held annually in Europe, Australia, and North America. Since the mid 1990s, the ICCS community has broadened its scope to include
formal concept analysis (FCA) and other tools and languages for representing and reasoning about concepts. Following is a sample of some currently active researchers on conceptual graphs, many of whom combine CGs with FCA and other notations for logic.{{col-begin}}{{col-break}}
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Resources
KonzeptgraphGráficos conceptualesGraphe conceptuel
(...as imported from WP)
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