[Haskell-beginners] Type signatures returned with :t

:t Just True Just True :: Maybe Bool :t Left True Left True :: Either Bool b :t Right False Right False :: Either a Bool

What am I being told here? It seems data Maybe a = Just a | Nothing data Either a b = Left a | Right b are both straightforward parameterized types, but Maybe doesn't give me a type parameter back, while Either does, and in different order, different names (a becomes b; b becomes a) depending on which variable I invoke. What deeper lore am I not seeing here? -- ⨽ Lawrence Bottorff Grand Marais, MN, USA borgauf@gmail.com