[Haskell-cafe] mutually recursive types

Hi, I am learning the haskell programming language and had tried to define the following types: type Scenario = (String, String, [Step]) type Step = (String, Scenario, String, String, String) Notice that Scenario depends on a list of steps and Step has a dependence with scenario. I know that this is a kind of "bad smell".... in Haskell, are there any pattern or language idiom to deal with cyclical dependences? Regards, Rodrigo.