It does violate the perfect "Cartesian coordinates" normalization I described earlier, however I consider this is a permissible step up over the full normalizat

It does violate the perfect "Cartesian coordinates" normalization I described earlier, however I consider this is a permissible step up over the full normalization, because, while cutting down repetition (entirely), it still suggests a zero-ambiguity way to read off the values from the header cells.