/* 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