An html version of staircase.cql.
Created by Gady Costeff and Lewis Stiller.
CQL 5.1 example can be found at the website of GadyCosteff.
CQL 3.02
;;This filter file looks for queen staircases ;;search for a queen staircase. ;; ;;The "shift" and the "flip" commands are used to take the given sequence ;;and make sure it can be started from any square and any direction ;; ;;The "flipcolor" command is used to make sure that it works with black queens too. ;; Because there is no :variations keyword, this only searches for staircases in the ;; main line. ;; Because of the presence of both :shift and :flip commands, this query takes a long time. (match :pgn heijden.pgn :output staircase.pgn (position :sequence ((position Qa2) (position) (position Qb2) (position) (position Qb3) (position) (position Qc3) (position) (position Qc4)) :shift :flip :flipcolor ))
After executing this with "> cql Staircase.cql" there are 539 studies found in the Harold van der Heijden Database 2015.
NB. When you see {MATCH} in the text, it means that cql has found the position asked for.
Below only 5 studies are presented: