// Download horizontallysymmetric.cql
// PGN output when run on sample.pgn

/* Winning positions with more than 3 pieces that are symmetric
   when colors are swapped and the board is flipped about the
   horizontal bisector, sorted by number of pieces.

Note:the 6.1 version is slightly shorter but use the more obscure
colortype filter, which we are trying to phase out.
cql(input hhdbvi.pgn result 1-0)

S {
 F= makesquare (file S
                8-rank S +1)
 typename F==typename S
 S or
 {S F}
sort "npieces"   4