[marcosdumay]

Given the types: I = A + B; J = C; X = A; Y = B + C

Is I + J the same type as X + Y?

If your types are tagged, they aren't. Because that's what tags do.

[bombela]

My answer would be: No they are not the same type. Yes they have the same amount of bits representing them. They might have different RAM usage because of alignment.

[xigoi]

> Is I + J the same type as X + Y?

They are not the same, but they are isomorphic. Just like with (A×B)×C versus A×(B×C).

[paholg]

Okay? I don't know what point you're making.