haskell@gentoo.org Gentoo Haskell Haskell 98 semigroups In mathematics, a semigroup is an algebraic structure consisting of a set together with an associative binary operation. A semigroup generalizes a monoid in that there might not exist an identity element. It also (originally) generalized a group (a monoid with all inverses) to a type where every element did not have to have an inverse, thus the name semigroup. You can disable the use of the `hashable` package using USE=-hashable. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. If set we will not supply an instance of `Hashable`. You can disable the use of the `bytestring` package using USE=-bytestring. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. You can disable the use of the `containers` package using USE=-containers. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. You can disable the use of the `deepseq` package using `-f-deepseq`. Disabing this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. You can disable the use of the `text` package using USE=-text. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. You can disable the use of the `unordered-containers` package using USE=-unordered-containers. Disabling this is an unsupported configuration, but it may be useful for accelerating builds in sandboxes for expert users. provide instances for binary package provide instances for transformers package. ekmett/semigroups