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

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