[awirth]

Note, this is about https://en.wikipedia.org/wiki/Lattice_(order) as in partially ordered sets, not https://en.wikipedia.org/wiki/Lattice_(group) as in geometry (and used by lattice cryptography)

[chrispeel]

Thanks! Is there any relationship? Some of the graphical examples [1] in your first link look like they could have a relationship to lattices of the second link.

[1] https://en.wikipedia.org/wiki/Lattice_(order)#Examples

[danharaj]

The common generalization of semilattices and groups are inverse semigroups which are one way of capturing the idea of partial, or local, symmetries.

https://en.wikipedia.org/wiki/Inverse_semigroup

[vmilner]

I always find that name-clash very annoying.