and adding that third file into the same path it runs. Yay. It works. It produces the Figure and the Command Window reports
STOPPED
###### a316667 ######
Move: knight
Board: spiral
Condition: none
Data: 1, 10, 3, 6, 9, 4, 7, 2, 5, 8, 11, 14, 29, 32, 15, 12, 27, 24, 45, 20, 23, 44, 41, 18, 35, 38, 19, 16, 33, 30, 53, 26, 47, 22, 43, 70, 21, 40, 17, 34, 13, 28, 25, 46, 75, 42, 69, 104, 37, 62, 95, 58, 55, 86, 51, 48, 77, 114, 73, 108, 151, 68, 103, 64, 67, 36
Sequence finite, at step 2016, square 2084 is visited, after which there are no unvisited squares within one move.
#####################
So what a learning curve for me. I see now what went wrong. When the original author posted his code he forgot about the support code. Hence the error. With the code restored/rewritten with grateful thanks, we now have the expected result.
With many, many thanks. What a story to share at the next Mathsjam next week.
In lines 19 to 33 of the original code, there is mention of the king, queen, bishop and rook. Can the same code be used for that? How do I tell it to do the king for instance?
Simon