An html version of kozirev.cql. Created by Gady Costeff and Lewis Stiller.

; This CQL file illustrates how to search for echoes in which there is some "give"; that is, it is not a perfect echo.
; The motivation for this example was to search for studies similar to the beautiful 1995 study by Kozirev in which a stalemate configuration with 
; Kd1, Bd2, kd3, bd4 and Qe5 recurs rotated 90 degrees but without a pawn elsewhere on the board
;
; To do this we limit the search 
; Find games in which there are two 
; positions P1 and P2, such that P2 is reached by a flip or transform from P1 (except for a couple of pawns at most)
; with the same side to move, such that P1 is a stalemate, and such that 
; at least 3 squares differ between P1 and P2, and such that at most 2 non-empty squares are the same
; between P1 and P2


(match
 :pgn heijden.pgn
 :output kozirev.pgn
 (position
  :stalemate
  :markall	
  :piececount [KkRrQqNnBb] 4 100	; Make sure the position is reasonably interesting
  :relation (:shift			; allow shifts
	     :missingpiececount [Pp] 0 2
	     :newpiececount [Pp] 0 2
	     :samesidetomove		; same side to move in P1 and P2
	     :originaldifferentcount 3 100 ; P1 and P2 must differ in at least three squares
	     :originalsamecount 0 2	; P1 and P2 cannot coincide in more than 2 nonempty squares
	     :flip)			; allow flips
  :variations				; search in variations

  )
 )

After executing this with "> cql Kozirev.cql" there are 27 studies found in the Harold van der Heijden Database V 2015.
The output kozirev.pgn is taken as input in the next step.

An html version of kozirev2.cql

; This CQL file illustrates another way to search for echoes (shifted or flipped) in which there is some "give"
; that is, it is not a perfect echo.
; The motivation for this example was to search for 
; studies similar to the beautiful 1995 study by Kozirev in which a stalemate configuration with 
; Kd1, Bd2, kd3, bd4 and Qe5 
; recurs rotated 90 degrees but without a pawn elsewhere on the board
;
; To do this we limit the search to non-pawn pieces
; Find games in which there are two 
; positions P1 and P2, such that P2 is reached by a flip or transform from P1
; with the same side to move, such that P1 is a stalemate, 
; at most 1 non-empty square is the same
; among the non-pawn pieces of P1 and P2


(match
; :pgn kozirev.pgn
 :pgn kozirev.pgn
 :output out.pgn
 (position
  :stalemate
  :markall	
  :piececount [KkRrQqNnBb] 4 100	; Make sure the position is reasonably interesting
  [KkRrQqNnBb]                          ; the pattern
  :relation (:shift			; allow shifts
	     :pattern                   ; ignore pawns
	     :samesidetomove		; same side to move in P1 and P2
	     :originalsamecount 0 1	; P1 and P2 cannot coincide in more than 2 nonempty squares
	     :flip)			; allow flips
  :variations				; search in variations

  )
 )

After executing this with "> cql Kozirev2.cql" there are 23 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: