promotion tricks for Retractor #7
Description
Hi thanks for all your work. I think Retractor is good enough to be really useful and I am now arguing in PDB that Popeye + Retractor + proof game is enough for C+ for problems involving e.g. en passant rights. Well done!
I will start now to point out individual areas where Retractor is still missing stuff.
P0003529 is a common situation where an edge pawn must promote without capture, thereby disrupting castling rights. Currently, Retractor does not object if I freeze wRa1.
In P0005275 (a), Retractor suggests d2-d4, but this is not possible because wPe can only promote on e8, which is light square. So wBb6 is impossible.
ADDED: 5-Dec-2021
In P1108614, Retractor suggests KxB or KxN. But two captures are required to promote 4 pawns from f,g,h files. So there are no spare units for either K to capture.
In P1271271, Retractor proposes wSg3xRf1. This is not possible because (due to bPd7) Black requires 4 captures to promote RRB. (wBc1 was captured at home by an officer.)
Thanks again!