|PAO(PA):||(0,1) Chinese. Chinese piece operating along Rook lines: moves as Rook, but captures only by hopping over a hurdle to any square beyond.|
|Anti-Circe:||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 allowed in Anti-Circe Calvet and not allowed in Anti-Circe Cheylan. 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.|
|stipulations||'Proca Retractor', '-N & s#1'|
|-N & s#1:||The stipulation means: retract N moves and than selfmate in 1.|
|Proca Retractor:||The one of the Defensive Retractors, where 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.
No. 1757 Klaus Wenda
original - 13.09.2023
Ded. to Hanspeter Suwe to his 75. birthday
PAO g2, g4
Solution: (click to show/hide)
--Sorry, no animation for this kind of problems (JV)
Without bSb1 White would suddenly reach his goal:
1.Ke1:R/S/PAf2(Ke1) & fw. 1.Sg5+ PAg2:g5(PAg1)#
A decoy of this S is requested.
1.Kb3:PAa3(Ke1)! a5-a4+ 2.Kc2-b3 b2-b1=S+ 3.Kc1-c2 b3-b2+ 4.c5:d6ep(d2) d7-d5 5.Rd1:Pd2(Ra1) d3-d2+ [already now 6.f2:Be3(e2)? Bd4-e3+? 7.0-0-0!, but 6...Rd2-a2+! prevents castling. A draw pendulum forces the rook to unpromote] 6.Kd2-c1! Ra1-a2+ 7.Kc1-d2 Ra2-a1+ [a2-a1=R+?] 8.Kd2-c1 Ra1-a2+ 9.Kc1-d2 a2-a1=R+[forced] 10.f2:Be3(e2) Bd4-e3+! 11.0-0-0! & fw. 1.S:d4(Sg1)+ PAg4:g1(PAg1)#[both Paos change, compared with the basic attac, the role of mate giving unit/hurdle; ...& fw. 1.Sg5+? PAg2:g5(PAg1)+ 2.Kd2! fails now but the new possibility to capture bBd4 brings compensation]
1.Kb3:a3(Ke1)? a5-a4+ 2.Kc2-b3 b2-b1=S+…9.Kc1-d2 a2-a1=R+?
turns out to be illegal due to the capture-balance: b pawns would have captured 8x but only 7 w units are missing. W would have been forced to break off the pendulum
...2.Kc3-b3 b2-b1=S+ 3.? W cannot arrive on 1st rank with tempo.
...4.e5:d6ep(d2)? d7-d5...10.f2:Be3(e2) Bc5,b6,a7-e3+ 11.0-0-0 & fw. 1.? there is no capture-object on d4 ...6.Kd2-c1 Ra1-a2+ 7.f2:Be3(e2)? Bd4-e3+ 8.Kc1-d2 Ra2-a1+ 9.0-0-0 & fw. 1.S:d4(Sg1)+ PAg4:g1(PAg1)# but…8. Kc1-d2 Bh8-d4+! parries, W must continue the pendulum.
Unpromotion of bS/bR, w ep-capture, w castling in the retro-play Valladao-Thema In the uncapturing moves W1/W5 K&R leave the game array position [= 2x „antizielelement“] and return in W11.