Jaap Scherphuis introduced The Arithmachinist by Henry Goldman in his post Goldman's Transformation Puzzle.
In the book I found a curious figure on p.52. I wonder what it means. Could you let me know?
I have posted this question on Jaap Scherphuis's post as an answer. Some users commented as follows:
I have pondered that too, but have not figured out what it means, apart from it being a latin square. – Jaap Scherphuis 9 hours ago
Also, a sudoku square. – P.-S. Park 8 hours ago
Nice. Also the main diagonal is in order 1 to 9, though the other diagonal and the broken diagonals don't seem to have anything special. – Jaap Scherphuis 8 hours ago
The other diagonal still has the 1-9 digits, just not in order – El-Guest 8 hours ago
it seems a solved sudoku problem to me with diagonal is 1 to 9. – Oray 7 hours ago