8 and 31, with 'the disk b', while the
denomination of other selected disks is a color disk. Another criteria
stands in connectives 'then' in 3 (reenforced by at the time in 4), 23, 28.
The criteria established with connectives can be considered as hierarchicaly
higher than criteria with the change of denomination of selected disk.    
- criteria at situational level : change in the denomination of the peg;
example in 4, 6, 10, 21, 30 (color disk), and in 18 (on the disk c).
Furthermore another criteria has