OK, I see your point better now. You're saying that reasoning about a type algebraically is more of a perspective, not a fundamental statement about the type it

OK, I see your point better now. You're saying that reasoning about a type algebraically is more of a perspective, not a fundamental statement about the type itself. I think I could get behind that. :) For what it's worth, not all functional languages emphasize the ADT notion per se. E.g., the Ocaml manual generally talks about records, tuples, and variant types; "algebraic" really only comes up with GADTs are discussed.