No.902,903 (EB)

No.902, 903 by Erich Bartel – The important role of promotions in two different problems. (JV)

Definitions:

PWC: When a capture is made, the captured unit (except a King) is replaced on the square the capturing unit just leaves. A Pawn is immovable on its 1st rank.

Alphabetic Chess: The squares are considered in the order a1, a2…a8, b1…b8, c1 and so on to h8. At each turn, only the unit standing on the square which comes earliest in this order may move. However check and mate are normal.

Madrasi: Units, other than Kings, are paralysed when they attack each other. Paralysed units cannot move, capture or give check, their only power being that of causing paralysis. Madrasi RI (rex inclusive): the rule applies to Kings as well, so the two Kings may stand next to each other.

Chameleon Chess: All pieces on the board which are displayed as orthodox Q, R, B, S, are Chameleons. A Pawn can promote only in Chameleon-pieces.

Disparate PY: If one side makes a move with a piece of type “x” (black, white, neutral, half-neutral, etc., King included), the other side cannot answer immediately by moving a piece of the same type “x”. (For example: white Qc1, black Ka8,Qa7 – mate in 1 move. After 1.Qc8#, Black is mated because 1…Qb8? is illegal. The mate is possible also with the neutral nQc1 – after 1.nQc8#. Black cannot move the same neutral Queen.) Every Pawn’s promotion is a Pawn’s move, therefore after such promotion (into any possible piece) the other side cannot answer immediately with its Pawn. We can say that after the move of the figure of type “x” any enemy figure of type “x” falls under Half-moving paralysis. This paralysis disappears immediately on the next half-move, if the opponent plays with another piece of type “y”. (“Disparate PY” is implemented as “Disparate” till the latest version of Popeye, PY 4.73. In WinChloe this version of Disparate is available starting version 3.32.)

Gnu(GN): Knight+Camel. Can move like a (1,2) Leaper and like (1,3) Leaper.

Lion(LI): Moves along Queen lines over another unit of either color to any square beyond that unit. A capture may be made on arrival, but the hurdle is not affected.

Okapi(OK): a piece combining the powers of Knight and Zebra.

Zebra(Z): (2,3) Leaper.

Bucephale(BU) (=Root-25-leaper): (0,5 or 3,4) Leaper – moves by the diagonal of a rectangle whose length is equal to the square root of 25.