Dear All,
Apologies if this has already been discussed: I would suggest to reformulate a paragraph in the introduction of the CRMbase document about properties with identical domain and range. See here:
https://docs.google.com/document/d/1_3J5e6wscwNEQzPqpBfWBmoOiHoBmAx_o8_…
Best,
Wolfgang
Post by Christian-Emil Ore (28 October 2024)
It is clear that having the same domain and range is not a sufficient condition for a property to be either symmetric or transitive as your example with P152 has parent (is parent of) clearly demonstrates. Also "Properties that have identical domain and range are either symmetric, asymmetric or neither." covers all cases and is a tautology. Maybe it is better to reformulate the paragraph to
"Symmetric and transitive properties have identical domain and range. Instantiating a symmetric property implies that the same relation holds for both the domain-to-range and the range-to-domain directions. An example of this is E53 Place. P122 borders with: E53 Place. The names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading.
Properties with identical domain and range that are not symmetric, such as E41 Appellation. P139 has alternative form (is alternative form of): E41 Appellation, have a parenthetical form that relates to the meaning of the inverse direction."
Best,
Christian-Emil
Post by Stephen Stead (28 October 2024)
This looks good to me
Stephen Stead
Post by Wolfgang Schmidle (28 October 2024)
This would be version 1 with a better first sentence, and split up into two paragraphs. Just one thing: Transitivity plays no further role here, so if it is mentioned, perhaps reflexivity should be mentioned as well? As in
Symmetric, transitive and reflexive properties have identical domain and range.
Best,
Wolfgang
Post by Daria Hookk (28 October 2024 --personal communication)
Your mean symmetric property is synonym and strictly speaking has no direction for the application like "to be brother of"?
Being interested in (non-symmetric),
Daria Hookk
Post by Christian-Emil Ore (28 October 2024)
A symmetric, reflexive and transitive relation is what we call an equivalence relation (like equality)
Without reflexivity it like "siblinghood" (with same pair of parents).
Chr-E
Post by Martin Doerr (28 October 2024)
Dear all,
Thank you Wolfgang for spotting the problem!
I think we are patching here. The full paragraph
- Properties that have identical domain and range are either symmetric or transitive. Instantiating a symmetric property implies that the same relation holds for both the domain-to-range and the range-to-domain directions. An example of this is E53 Place. P122 borders with: E53 Place. The names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading. Transitive asymmetric properties, such as E4 Period. P9 consist of (forms part of): E4 Period, have a parenthetical form that relates to the meaning of the inverse direction.
appears as part of the naming conventions. The concepts of transitivity, reflexivity and symmetry are extensively explained in the terminology section. No reason to repeat them here, this causes pitfalls when updating the text. The only reason, why this should appear under "Naming Conventions" is the missing inverse label.
Therefore, I propose to replace the paragraph by:
- Instantiating a symmetric property implies that the same relation holds for both the domain-to-range and the range-to-domain directions. Therefore the names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading. An example of this is E53 Place. P122 borders with: E53 Place (see also the definition of "symmetric" in the section "Terminology".)
It could even be shorter:
- The names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading. An example of this is E53 Place. P122 borders with: E53 Place. See the definition of "symmetric" in the section "Terminology".
Opinions?
Cheers,
Martin
Post by Christian-Emil Ore (28 October 2024 --personal communication)
Your last alternative is in my opinion the best:
- The names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading. An example of this is E53 Place. P122 borders with: E53 Place. See the definition of "symmetric" in the section "Terminology".
Chr-Emil
Post by Wolfgang Schmidle (28 October 2024)
- The names of symmetric properties have no parenthetical form, because reading in the range-to-domain direction is the same as the domain-to-range reading. An example of this is E53 Place. P122 borders with: E53 Place. See the definition of "symmetric" in the section "Terminology“.
I think this version is clear and gets to the point.