Added redirect for ordered groupoid(s).

]]>Fixed typo

Anonymous

]]>Added reference to Wagner-Preston theorem

]]>Yes, it is called Wagner-Preston and not Cayley in this generalized setting, cf. https://en.wikipedia.org/wiki/Wagner-Preston_Theorem.

]]>Adding a “Cayley’s theorem” for inverse semigroups to show that any inverse semigroup can be realized as a semigroup of partial bijections of a set. I’m not sure if this is the same as the Wagner-Preston theorem.

]]>I say yes, to both things (and thanks). If anything else needs to be done, someone will come by.

]]>I just proved a “Cayley’s theorem” for inverse semigroups — that every inverse semigroup is isomorphic to a sub-semigroup of I(X) for some set X. Should I add this fact to the article? Should I also add a proof? I am new with contributing to the nLab so I don’t know how this works.

]]>Cartologies has been an interesting project!

]]>The edits were spurred by some side research, when I was looking into an MO question which was shut down by some of the usual gatekeepers there, and which wound up being the “Warning” subsection. I learned enough about the topic to make some edits there, that’s all.

However, it did reignite some possible interest in returning to my “cartologies” article on my personal web, which was left in limbo (like almost everything there, alas).

]]>Interesting. What are you up to ?

]]>Added a bunch of material to inverse semigroup under subsections of “Properties”.

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