it was so much time that I was thinking about it
I have succeeded in producing a first scheme
I was pushed by the test of study of the last wsc
it deals with a scheme that in a first moment it is introduced with multiple solutions and it doesn't have any single to be entered
it deals with finding the technique that allows to isolate a single
the identified single MUST be inserts with the mouse by clicking on the candidate so a further given is disclosed that makes the solution unique
(still I have a doubt, perhaps there is a superior technique that allow to place other different single from the one produced by the computer that uses a personal valutation of difficulty)