[Retros] Add pieces, 4th update

[Alain BROBECKER]

Dear retro fans,

As usual, new version can be found here:
  http://abrobecker.free.fr/chess/addpiece.pdf

Considering suggestions, remarks:
* "Add minimal number of pieces" is the same as
  add N pieces with an illegal position? So it's
  just a question of modifying the stipulation?
* Aa, Ac, Ca, Cc: i wonder if it's worth it, it seems
  all C are Cc? (can someone prove me wrong and find
  a Ca?).
* illegal/legal positions = "add pieces so that position
  becomes/remains legal" seems to  me the more interesting
  subdivision. For the moment no problem needs that
  subdivision, but if one comes across (eg N1A? with
  illegal position) i will consider changing categories.
* I'm ashamed of NA2, which, as NA14, is not very
  interesting (and unlike N1AK IMO). Shall we consider
  problems with K additions apart from others, as in NA1?

I will probably calm down a bit on the updates, but
i hope we'll have enough news for next WE.

Best regards, Alain


Alain Brobecker (abrobecker at yahoo.com) |_  _  _ |_
http://abrobecker.free.fr/             |_)(_|(_|| ) of  Arm's Tech