- bag-union bag1 bag2 ...procedure
- bag-intersection bag1 bag2 ...procedure
- bag-difference bag1 bag2 ...procedure
- bag-xor bag1 bag2procedure
Return a newly allocated bag that is the union, intersection, asymmetric difference, or symmetric difference of the bags. Asymmetric difference is extended to more than two bags by taking the difference between the first bag and the union of the others. Symmetric difference is not extended beyond two bags.