An html version of rookrectangle.cql. Created by Gady Costeff and Lewis Stiller.
;; look for positions where a rook circles in a 4x3 rectangle
;; we use the rectangle g2, d2, d6, g6 together with shift and flip
;;
(match
;:pgn tmp.pgn
:pgn heijden.pgn
:output rookrectangle.pgn
:forany piece [Rr]
(position
$piece[g2]
:and (
(position :gappedsequence ((position :movefrom $piece[g6,d2] :moveto ?g2)))
(position :gappedsequence ((position :movefrom $piece[d6,g2] :moveto ?d2)))
(position :gappedsequence ((position :movefrom $piece[d6,g2] :moveto ?g6)))
(position :gappedsequence ((position :movefrom $piece[g6,d2] :moveto ?d6)))
)
:shift :flip
))
After executing this with "> cql RookRectangle.cql" there are 8 studies found in the Harold van der Heijden Database V 2015.
NB. When you see {MATCH} in the text, it means that cql has found the position asked for.
Below only 4 studies are presented: