# Property talk:P5350

Active discussions

## Documentation

Alexander polynomial
invariant of a knot or link. Use 't' as variable and list monomials in decreasing order.
RepresentsAlexander polynomial (Q1634206)
Data typeMathematical expression
Exampleunknot (Q1188344)${\displaystyle 1}$
trefoil knot (Q168620)${\displaystyle t-1+t^{-1}}$
three-twist knot (Q7797291)${\displaystyle 2t-3+2t^{-1}}$
Sourcehttp://katlas.math.toronto.edu/wiki/Main_Page
Lists
Proposal discussionProposal discussion
Current uses
 Total 2,985 Main statement 2,982 99.9% of uses Qualifier 3 0.1% of uses
[create Create a translatable help page (preferably in English) for this property to be included here]
 Type “link (Q1760728)”: element must contain property “instance of (P31)” with classes “link (Q1760728)” 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/P5350#type Q1760728, SPARQL, SPARQL (new)

## Redefining domain of this property

Alexander polynomial (P5350) is currently defined as being a property of members of the set of knot (Q1188853). The Alexander polynomial actually seems to be defined over the set of link (Q1760728), of which knots are a proper subset. (See, for example, this paper.)

Should I just boldly edit the property to change its domain, which as far as I can see would not break anything because of the existing set inclusion relationship between knots and links, or is there a procedure I should go through to do this? -- The Anome (talk) 12:57, 16 July 2020 (UTC)

@The Anome: that looks very consensual, please just do it! − Pintoch (talk) 13:10, 16 July 2020 (UTC)
Support Sounds good to me, thanks! ArthurPSmith (talk) 13:20, 16 July 2020 (UTC)
Support Do it! Lymantria (talk) 14:03, 16 July 2020 (UTC)
Done Thank you! I've also done the same with Jones polynomial (P5352), see reference here. -- The Anome (talk) 18:55, 16 July 2020 (UTC)