That Mateo puzzle
I remember spending a lot of time and paper on a puzzle involving Mateo.
It was really difficult. I think it had a lot of clues of my favorite form: "Of A and B, blah blah."
You will probably have to make several passes through the clues as you extract everything you can from clues of that form. Basically, you have to keep going through the clues until you make a pass without adding any additional Xs.
If there are clues where category members are a fixed distance from each other in the same category and there are only two choices left for each, remember to X out the overlapping cells for the other members.
If there are multiple ordering clues that involve the same category member, remember to X out the members at the ends. E.g. if A < B and B < C, then A cannot be C.
If you have a lot of Xs, then this puzzle is probably be solved by looking at pairwise intersections of rows and columns in different categories. Anywhere you find a null intersection, you can place an X somewhere. Hopefully it will be a new one that you don't already have.
Oh, and remember to place all the Xs for the "Either..." and "Neither ..." clues. E.g. Either A or B is blah. A and B aren't the same person, so if they aren't in the same category, remember to X out their intersection.
If this doesn't get you to that first positive, then post the info, and I'll see if I can get you there.
Last edited by zenobia43; 06-16-2012 at 01:46 AM.