Similarly, could we replace `__first2` here with `__left_bound_seq_2`? If elements prior to the left bound don't intersect with sequence 1, then they shouldn't affect the difference, right?

[SergeyKopienko]

Similarly, could we replace __first2 here with __left_bound_seq_2? If elements prior to the left bound don't intersect with sequence 1, then they shouldn't affect the difference, right?

Originally posted by @danhoeflinger in #2320 (comment)