Yeah. HKTs are one particular instance, though even Scala doesn't necessarily do particularly well on those compared to e.g. Haskell (well, GHC, really). (It s

Yeah. HKTs are one particular instance, though even Scala doesn't necessarily do particularly well on those compared to e.g. Haskell (well, GHC, really). (It seems subtyping and higher-order reasoning just don't mix well. Undecidability abounds, unfortunately. I tend to prefer higher-order reasoning over subtyping.)