模块文档模块Data.BooleanAlgebra类型类class (Lattice a) <= BooleanAlgebra a where complement :: a -> a类型类实例instance booleanBoolean :: BooleanAlgebra Boolean价值观booleanNegate :: Boolean -> Boolean not :: forall b. (BooleanAlgebra b) => b -> b模块数据有界半格类型类class (JoinSemilattice l) <= LowerSemilattice l where bottom :: l class (MeetSemilattice l) <= UpperSemilattice l where top :: l类型类实例in