One thing that has to hold of the groups, and does not yet: two of them hold the same value, or one of
them carries a pin.
Collected rather than applied on the spot, since establishing either may establish further ones - merging
two groups meets their pins, and meeting two pins merges the groups their positions name - and recursing
would re-enter a merge halfway through the one running.
One thing that has to hold of the groups, and does not yet: two of them hold the same value, or one of them carries a pin.
Collected rather than applied on the spot, since establishing either may establish further ones - merging two groups meets their pins, and meeting two pins merges the groups their positions name - and recursing would re-enter a merge halfway through the one running.