/Я language (β)/Behaviour/Whirl/

Same behaviour as Plane, but works only for List and terminates on empty lists:

> [ [ A , B , C ] , [ E , F ] , [ G ] ] `yok` Whirl = [ A , B , C , E , F , G ]
> [ [ A , B , C ] , [ ] , [ E , F ] ] `yok` Whirl = [ ]