# Property talk:P7235

Active discussions

## Documentation

in defining formula
symbol used in the defining formula (P2534)
Representsvariable (Q50701), identifier (Q1773882), pronumeral (Q93421351)
Data typeMathematical expression
Usage notesUse as main value or qualifier to calculated from (P4934) to indicate the symbol used to reference a quantity in the defining formula (P2534).
Example
According to this template:
According to statements in the property:
f-number (Q862169)${\displaystyle N}$
magnetic flux density (Q30204)${\displaystyle \mathbf {B} }$
When possible, data should only be stored as statements
See alsodefining formula (P2534), calculated from (P4934), quantity symbol (LaTeX) (P7973)
Lists
Proposal discussionProposal discussion
Current uses
 Total 2,585 Main statement 681 26.3% of uses Qualifier 1,904 73.7% of uses
[create Create a translatable help page (preferably in English) for this property to be included here]
 Item “defining formula (P2534)”: Items with this property should also have “defining formula (P2534)”. (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7235#Item P2534, SPARQL, SPARQL (new)
 Item “calculated from (P4934)”: Items with this property should also have “calculated from (P4934)”. (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7235#Item P4934, SPARQL, SPARQL (new)
 Scope is as main value (Q54828448), as qualifier (Q54828449): the property must be used by specified way only (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7235#scope, SPARQL, SPARQL (new)
 Allowed entity types are Wikibase item (Q29934200): the property may only be used on a certain entity type (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7235#allowed entity types, SPARQL (new)
 Single value: this property generally contains a single value. (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7235#Single value, SPARQL, SPARQL (new)

### Relationship to has-part

From the propoerty creation discussion:

## Label

Using 'symbol' in labels is a better option. When I first saw this property, I didn't know what it was about. Wostr (talk) 14:27, 26 April 2020 (UTC)

Support I also like more "symbol in defining formula". One might argue that "short is good", but in this case clarity might help. Toni 001 (talk) 18:14, 26 April 2020 (UTC)
• I don't think the property is meaningful without defining formula (P2534), especially, it shouldn't be used without a P2534 being present.
At some point we should be able to do a complex constraint that ensures the value of this property is present in P2534 (e.g. "words" at Q91798342#Q91798342\$8ae98ac0-4309-6712-81f7-74c4b584cb1b in Q91798342#P2534).
If there are no parts of P2534-values that aren't covered by the proposed change, please go ahead. --- Jura 07:51, 27 April 2020 (UTC)
e.g. at Poisson's ratio (Q190453) we need to make sure that this property isn't confused with quantity symbol (LaTeX) (P7973) also present there. --- Jura 08:00, 27 April 2020 (UTC)
Yes. For new users we could state somewhere prominently that:
1. quantity symbol (LaTeX) (P7973) contains any symbol typically used for a given quantity
2. in defining formula (P7235) contains exactly one symbol, namely, the one used in the defining formula (P2534)
(This should be clear from the current label and description, but new users could miss this fine distinction.) Toni 001 (talk) 09:43, 27 April 2020 (UTC)
I added some usage instructions. Toni 001 (talk) 09:55, 27 April 2020 (UTC)
I wouldn't really count on people reading that. It was meant for a feature that was never implemented. In the meantime, property descriptions can be used. For properties, there is a risk that people already don't read that. --- Jura 05:38, 28 April 2020 (UTC)
Thanks for the hint about the non-implemented feature. I had noticed the mention of it in the description of Wikidata usage instructions (P2559) and was wondering what it meant. (By the way, I'm not too worried about "people not reading the instructions". This might happen for some casual user passing by, but once they start seriously contributing they'll need and find that information and be happy that it's there.) Toni 001 (talk) 08:42, 28 April 2020 (UTC)
Return to "P7235" page.