4 ms·> Haskell doesn't have sum types Say what?..by icrbow 5y ago> Haskell doesn't have sum types Say what?..tome 5y agoI think it's because `Either a b` contains all of `undefined`, `Left undefined` and `Right undefined`. In other words, a technicality.hutrdvnj 5y agoAnd this is not even the bottom of Haskell's unsoundness.