>But currently AND/OR in Calcite is always binary operator I guess we might want to add multi-arg AND in the future to address AND(AND(AND(...))) issues. I know IntelliJ IDEA switched to multi-arg "+" and similar representations to reduce the complexity of certain operations.
PS. Even though we can have a nice unordered hash function, we still need to implement `equals`, and it looks like we need to have normalization there. Do you suggest we should implement `equals` in such a way that it does not need to normalize the tree? Is there an approach? I see currently the implementation is normalizing both expressions every time `equals` is called. On top of that, it s not clear how it should behave with deep normalization. Vladimir
