Oooooh... So you're saying that  List1 List2 List3 are actually headers and the list items descend below each header. So the data should really look something like
List1 List2 List3
  a     a     b
  b     b     c
  c     d     d
translating (to pseudocode) as
List1 = [qw{a b c}];  List2 = [qw{a b d}];  List3 = [qw{b c d}];

That's a much better guess than mine, and from the tone of abd's reply may even be right. When I first saw your post, I thought you'd lost your mind, but I've switched to ++.

In reply to Re^2: Comparing and Aligning arrays by AnomalousMonk
in thread Comparing and Aligning arrays by abd

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