No.1223.2 (GW & KW)

The -7 & #1 stipulation means: retract 7 moves and than mate in 1 move.

Defensive Retractor: In Defensive Retractors, White and Black retract (take back) a given number of moves (-n moves), in order to reach a position in which a forward stipulation (e.g. #1, s#1) is met. Given a choice, Black will retract those moves that avoid or delay White’s goal. Unless otherwise stated, Black may defend by mating White through a forward move, if such an opportunity exists after one of Black’s retractions.
The different kinds of Defensive Retractors only differ in the way uncaptures are handled, of course only legal uncaptures are allowed:

• In Proca Retractors the retracting side decides, if and what man was uncaptured.
• In Hoeg Retractors the opposite side decides, if and what man was uncaptured.
• In Klan Retractors always White decides, if and what man was uncaptured.
• In Pacific Retractors there are no uncaptures at all.

Anti-Circe (Cheylan): After a capture the capturing piece (Ks included) must immediately be removed to its game array square (necessarily vacant, else the capture is illegal). Captures on the rebirth square are not allowed. Game array squares are determined as in Circe: R, B & S go to the square of the same colour as the capture; Ps stay on the file of capture; fairy pieces go to the promotion square of the file of capture.

The Magic Wandering Unit (MWU) – Convention

1. An MWU moves and acquires the opposite colour on its arrival square. In doing so it preserves the magic power (mp).

2. The magic power is strictly bound to the existence of a unit (except kings). On principle, blank squares do not contain any magic power.

3. Apart from all other (ordinary) units there is only one single MWU ever to be seen on the borad.

4. As to capturing units the following practice has got legal force:

a) An MWU captures and, simultaneously, acquires the opposite colour on the square of capture.

b) An ordinary unit captures an MWU that disappears from the board. At the same time, the capturing unit acquires the mp, thus mutating to an MWU and acquiring the opposite colour on the square of capture.

c) A king captures an MWU. Then the MWU disappears as well as does the mp. The king is, of course, in no way influenced by the mp.

5. As to capturing units under the condition of AntiCirce the following practice has got legal force:

a) An MWU captures – two types are to be classified according to the procedure of changing the colour and the tranfer on to the original square. Type I: the capturing unit acquires the opposite colour on the square of capture and is then transferred to the original square corresponding to the new colour. Type II: The capturing unit is first transferred to its original square and then acquires the new colour. Thus the MWU transports the mp to a new square with each of its captures in the same manner as it does with capture-free moves.

b) An ordinary unit captures an MWU, see (4b), yet as to the new colour and the transfer to an original square, see (5a).

c) A king captures an MWU, see(4c) and wK goes to e1, bK to e8.

6. Whenever there are uncaptures in retro play no additional new MWUs can emerge on the board, see (3).

7. With uncapturing units in retro play under the condition of AntiCirce, the following practice has got legal force:

a) An ordinary unit uncaptures exclusively from he original square of its colour.

b) With type II a whiote MWU can only uncapture from an original square of arrays 7 and 8; a black MWU only from arrays 1 and 2 (see change of colour accoding to (5a). White MWUs on arrays 1 and 2 as well as black MWUs on arrays 7 and 8 can only take back back capture-free moves.

8. Other general power exerted by an MWU works out in the same manner as with ordinary units.

9. In retro problems it must be ensured in any case that the MWU can legally be played back to an original square. If there is evidence of the impossibility of that (virtual) action, the position is illegal!