Reading this https://www.cefns.nau.edu/~edo/Classes/CS396_WWW/Misc_docs/Haskell.html I'm a bit confused but think I understand what is meant by a *product *or *tuple *type constructor such as data Point a b = Pt a b Because Point has no "logical or," (|) of more than one possible value set such as data Color = Red | Green | Blue it is automatically a tuple type? Also, it has no possible "consing" -- does that play a role? data Things a = T1 a (Things a) | T2 a (Things a) | LastT a Things is also parameterized just like Point, but, again, Things is not a tuple type for the reasons above, e.g., just having one parameterized constructor means automatically a tuple type, right? LB