Sudoku solver

[ttw]

You're right. It seems to work here. I don't know why my particular case failed. Perhaps I should recreate the whole thing (this time in reals) and see what happens (I can do this in a couple of evenings.) All I lack are the logicals however I many be able to get around this.

I used the exact test that you posted and couldn't things to work on two different calculators (it worked on a third with older CAS). Now I have to see where I either tested wrongly or what conditions caused the failure. Just this alone reduces my code length about 1/3 for inner loops. I did have the word size at 9 bits but that seems OK now.

Thanks.