Other operators
The operators we have considered thus far apply to a single cube (or grid) argument. There are also operators that take two cube arguments. An immediate example is intersection. Intersection of two grids is always a grid, so there is nothing to worry about. Other operators, like union, produce results depending on the positions of the arguments. Although we can always either perform grid completion or deflate, the usability of such operators is questionable and it is not completely clear whether they contribute to the model in a meaningful way. The same applies to various joins. Some of them do make sense but are not discussed here.