[Retros] Parity Argument?

[Otto Janko]

Joost wrote:


> > > > Stanislav Vokal

> > > > Sachove Umeni, Nr. 130, 1997

> > > >

> > > > [r3k2r/1pppppp1/1p3n2/8/7P/P1NR1N2/1PPPP1P1/5RK1]

> >

> >Sorry, I forgot the stipulation: "The last move was w0-0. May Black 

> >castle now?"

> 

> And the twin was forgotten too: (b) Pb7->h7

> (Source: http://hep.upjs.sk/~vokal/xxr9710.html)


And it was the wrong problem too, this one has nothing to do with 
the parity argument. Any idea what else I have got wrong?  :-(((

Ok, let's start again:

---

R008 - Stanislav Vokal
Probleemblad, 1997

+---+---+---+---+---+---+---+---+

| r |   | b |   | k |   |   | r |

+---+---+---+---+---+---+---+---+

|   | p | p | p | p |   | p |   |

+---+---+---+---+---+---+---+---+

| p |   |   |   |   | p |   |   |

+---+---+---+---+---+---+---+---+

|   |   |   |   |   | p |   |   |

+---+---+---+---+---+---+---+---+

|   |   |   | P |   |   |   |   |

+---+---+---+---+---+---+---+---+

| P |   |   |   |   |   |   | P |

+---+---+---+---+---+---+---+---+

|   | P | P | P | P |   | P |   |

+---+---+---+---+---+---+---+---+

|   | R | B |   |   | R | K |   |

+---+---+---+---+---+---+---+---+       

12+12. The last move was w0-0. May Black castle now?
       a) Diagram b) Pf6 -> f7

[r1b1k2r/1pppp1p1/p4p2/5p2/3P4/P6P/1PPPP1P1/1RB2RK1]

Althought there is no odd/even argument in the solution, I think 
this problem can be seen as an example for the parity argument. 
Any objection? (This problem might be another example for the 
parity argument in the glossary of the Retro Corner.)

Best Regards,

- Otto Janko [mailto:otto at janko.at; http://janko.at]
-- Plausible Unmöglichkeiten sollten unplausiblen 
- Möglichkeiten vorgezogen werden. [Aristoteles]