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

;The Valladao task: Find studies in which en-passant, promotion, and castling all occur in the main line.


(match
 :pgn heijden.pgn
 :output valladao.pgn
 (position :enpassant)
 (position
  :movefrom [Kk]e?
  :moveto .[c?,g?]
  )
 (position :promote [NnBbRr])
)

After executing this with "> cql Valladao.cql" there are 22 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: