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: