PSIs for Extrinsic Relations

Published Subject Indicators for Extrinsic Relations

PSI Metadata

Description	When two entities are associated by a binary HAS relation, but neither one depends for its existence on the other, in Conceptual Graphs that relationship is said to be extrinsic. The key test on the related "correlative" roles of such relations is offered at the above link: neither one can be a Component (PART or PROPERTY) of the other one. This PSI set addresses with this open-ended class of associations by exploring examples cited in the paper above. It seems to confirm the working hypothesis that these relation types are often just ad hoc links between two Participant roles of a larger Situation model, to which both of these roles are intrinsically related. This may be easiest to see in CTM, where associations need not be binary. But when they are, relating their role types to those of Situation types may make them much easier to formalize and understand. Even if ad hoc, they conceptually then build upon more solidly constrained models of intrinsic relations. Major case roles (only) are indicated for the examples below, with quick guesses at their base types and cardinality - 1 or N (> 0) within such a Situation model.
Publisher	Lexikos Corporation
Creator	Dan Corwin
Language	http://www.topicmaps.org/xtm/1.0/language.xtm#en
Version	2004/08/01
Status	Pre-release CTM 1.0 draft for comment
Date Published	2004/07/17

Index Of Subjects

Counseling	http://www.lexikos.com/psi/ctm/extrinsic/#1
*...Lawyer	http://www.lexikos.com/psi/ctm/extrinsic/#11
*...Client	http://www.lexikos.com/psi/ctm/extrinsic/#12
*...Counsel	http://www.lexikos.com/psi/ctm/extrinsic/#13
Parenting	http://www.lexikos.com/psi/ctm/extrinsic/#2
*...Mother	http://www.lexikos.com/psi/ctm/extrinsic/#21
*...Child	http://www.lexikos.com/psi/ctm/extrinsic/#22
*...Father	http://www.lexikos.com/psi/ctm/extrinsic/#23
Sequencing	http://www.lexikos.com/psi/ctm/extrinsic/#3
*...SUCC	http://www.lexikos.com/psi/ctm/extrinsic/#31
*...Base	http://www.lexikos.com/psi/ctm/extrinsic/#32
*...Pred	http://www.lexikos.com/psi/ctm/extrinsic/#33
Possessing	http://www.lexikos.com/psi/ctm/extrinsic/#4
*...Owner	http://www.lexikos.com/psi/ctm/extrinsic/#41
*...POSS	http://www.lexikos.com/psi/ctm/extrinsic/#42
Causing	http://www.lexikos.com/psi/ctm/extrinsic/#5
*...BCAS	http://www.lexikos.com/psi/ctm/extrinsic/#51
*...Effect	http://www.lexikos.com/psi/ctm/extrinsic/#52

Counseling

Published Subject Identifier: http://www.lexikos.com/psi/ctm/extrinsic/#1

The meaning of the English verb counseling seems involved. The binary Lawyer-Client relationship can be easily understood as one linking two case roles - both of which are already parts of a common situation model:

Lawyer = N: the AGNT who passes Counsel on behalf of the client
Client = 1: the BENF who gains because of the completed Counsel
Counsel = N: a THME comprising advice and formal legal actions

Neither lawyer nor client is part of the other one, but the shared situation disappears if either required role does. They are "correlative" only if one ignores this situation, which would seem to be a modeling error. The binary relation could do this implicitly iff both role-types were known to also be Parts of the larger situation type above.

Parenting

Published Subject Identifier: http://www.lexikos.com/psi/ctm/extrinsic/#2

Mother-Child relations show similar effects in this meaning of the Parenting verb. Note that here we can insist on exactly 1 parent of each sex, but N children seem fine. This is part of the constraints of the role types:

Mother = 1: a Player - older female parent of the Child
Child = N: the younger organism (THME) who was begotten
Father = 1: a Player - older male parent of the Child

Neither Mother nor Child is Part of the other. But even a basic grasp of their actual relationship should tap into a situation model at least as complex as the one above, which CTM would deem definitional to these role types.

Notice that the Parenting situation type one can with equal ease help define the Mother-Father relation, and with bit more effort, a formal spec for the extrinsic sibling relation.

Sequencing

Published Subject Identifier: http://www.lexikos.com/psi/ctm/extrinsic/#3

One simply cannot have a SUCC without some kind of sequence. The situation type below could indirectly help define several English verbs, and also some meanings for prepositions such as after and in between:

SUCC = N: Successor - something that comes after the THME
Base = 1: the THME - a focal point between the SUCC and Pred
Pred = N: Predecessor - something that comes before the THME

The situation type above should probably add some PROPERTY declaring the dimension of descriptors comprising the sequence: temporal, linear, numeric, etc. Then its model could become even more general and widely used, as each situation instance or subtype could specify that dimension overtly.

Most English preposition meanings seem to be extrinsic relations whose roles derive from similar types. A parser might generally fill in the dimension of each such situation instance from the types of the related role players, which would be semantically constrained so that the implied dimension from both had to match.

Possessing

Published Subject Identifier: http://www.lexikos.com/psi/ctm/extrinsic/#4

The POSS is correlative to its owner, but both roles are required parts of a common situation that defines possessing-like verbs. They would be fairly typical state verbs, each needing a STRT and/or CMPL descriptor to properly model its instances.

This extrinsic binary relation ignores such aspects, but if it were properly implemented, constraints requiring one or the other instances should be arranged:

Owner = 1: an EXPR who owns and controls the POSS entity
POSS = N: Possession - the THME within an ownership situation

In passing, we notice that this situation involves yet another idiosyncratic meaning for HAS, which may be exactly the reason it became an example of a binary relation.

Causing

Published Subject Identifier: http://www.lexikos.com/psi/ctm/extrinsic/#5

Causality generally involves two situations, one of which explains the existence of the other. As in the case of Possessing, some sort of Timing qualifier and constraints seem required to express all this properly, and insist that in instances, the Effect does not come earlier in time:

BCAS = 1: a cause (other situation) which explains the one under Effect
Effect = N: a situation caused by the other one cited under BCAS

Of all those presented here, this example of an extrinsic relation may be the most useful, as it concisely links two instances of a type that might otherwise go totally unrelated, and tells a meaty, informative story about them. All associations should be so expressive.