Non-match is, unfortunately, just as hard as match. Well...maybe not. Hmmm...If you don't really care *WHICH* entries matched, then all we need to do is find CR and DR that have no possible match. Hmmm...
Yes, I think we can do that.
Let me play with it...Ugh! Almost got there and then realized I wasn't detecting the case when there were, say, 2 more CR's of 30 than there are DR's of 30. I was only handling the case where there is only on mismatch. Double ugh. Not an easy problem.
An optimist sees the glass as half full.
A pessimist sees the glass as half empty.
A realist drinks it no matter how much there is.