# Property talk:P7973

Active discussions

## Documentation

quantity symbol (LaTeX)
symbol for a mathematical or physical quantity in LaTeX
Representsquantity symbol (Q1401551)
Data typeMathematical expression
Domainindividual quantity (Q71550118)
Usage notesAny symbol typically used to reference this quantity. For the symbol used in the defining formula (P2534), use in defining formula (P7235).
Exampleelectric charge (Q1111)${\displaystyle Q}$
group velocity (Q217361)${\displaystyle c_{\mathrm {g} }}$
mass fraction of water (Q76379025)${\displaystyle w_{\mathrm {H} _{2}\mathrm {O} }}$
Sourceunknown
See alsounit symbol (P5061), quantity symbol (string) (P416), title in LaTeX (P6835), in defining formula (P7235)
Lists
Proposal discussionProposal discussion
Current uses
 Total 1,527 Main statement 1,521 99.6% of uses Qualifier 6 0.4% of uses
[create Create a translatable help page (preferably in English) for this property to be included here]
 Type “individual quantity (Q71550118)”: element must contain property “instance of (P31)” with classes “individual quantity (Q71550118)” or their subclasses (defined using subclass of (P279)). (Help)Exceptions are possible as rare values may exist. List of this constraint violations: Database reports/Constraint violations/P7973#type Q71550118, SPARQL, SPARQL (new)
 Scope is as main value (Q54828448): 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/P7973#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/P7973#allowed entity types, SPARQL (new)

## Symbol/notation?

What's the difference from quantity symbol (string) (P416)? --Infovarius (talk) 20:56, 18 March 2020 (UTC)

This property (P7973) has datatype math, the other one has string, which was not enough to enter some symbols. Toni 001 (talk) 10:10, 19 March 2020 (UTC)

We are losing copyable information (math type can't be copy-paste directly). There's 2 variants: either to leave quantity symbol (string) (P416) or add qualifier Unicode character (P487) with older value. --Infovarius (talk) 13:32, 27 March 2020 (UTC)

One major glitch! This property doesn't allow cyrillic symbols! But there are usecases when Russians use cyrillic notation. --Infovarius (talk) 14:01, 27 March 2020 (UTC)

That's indeed an issue - LaTeX does not support all Unicode characters. Another shortcoming: I have not found a way to enter an upright \mu. In the long term we could consider a new datatype which allows directly entering MathML, which would probably solve all of those issues (an added benefit would be the possibility to enter semantic expressions - in addition to or instead of presentation syntax like LaTeX). Toni 001 (talk) 12:56, 30 December 2020 (UTC)

## Label

The label proposed in the discussion included "(LaTeX)". This was omitted on creation, so I had to add it now. --- Jura 10:37, 28 March 2020 (UTC)

## Italic and bold symbols

Following ISO 80000-1:2009 Quantities and units—Part 1: General (Q26711930), section 7.1.1: "... quantity symbols are always written in italic (sloping) type ...". This also applies to vector and tensor quantities, which in addition to being italic are printed bold (or with an arrow, see discussion above). To achieve both italic and bold font one can use \boldsymbol. I had originally entered symbols for vectors using \mathbf, but this makes the symbols upright. I'm going through all symbols now to use \boldsymbol instead. This will bring us a little closer to standard compliance.

Best wishes. Toni 001 (talk) 11:17, 30 December 2020 (UTC)