Likely meant to be lifting instances of Semigroup and Monoid through Dual: newtype Dual a = Dual {getDual :: a} instance Semigroup s => Semigroup (Dua

Likely meant to be lifting instances of Semigroup and Monoid through Dual: newtype Dual a = Dual {getDual :: a} instance Semigroup s => Semigroup (Dual s) where (Dual a) <> (Dual b) = Dual (b <> a) instance Monoid m => Monoid (Dual m) where mempty = Dual (mempty)