You could use the intersect function (type help intersect in the Command Window for details) to determine how many elements are common in any two rows of the matrix A, and if that number is greater than two, then you know to exclude that second row. If you were to start with the first row, you could then compare all others to it and remove those that have more than two elements in common:
% suppose A is your matrix from above
m = size(A,1);
rowsToRemove = []; % lis
for i=2:m % start with second row and iterate over all remaining rows of A
if length(intersect(A(1,:),A(i,:)))>2
% record this i as a row to remove
rowsToRemove = [rowsToRemove ; i];
end
end
% remove all rows from A that have more than 2 elements in common with row 1
A(rowsToRemove,:) = [];
A is now (perhaps) reduced in size, so repeat the above starting at the second row. Keep iterating in this manner until there you have reached the last row of the (reduced) A. And you're done.
