An html version of caterpillar.cql.

Created by Gady Costeff and Lewis Stiller.

CQL 5.1
; tripled contiguous pawns move up the board one rank cql(input heijden.pgn sort matchcount 1 100) flipcolor shift { Pb2 Pb3 Pb4 next( move from Pb4 to b5 any+ move from Pb3 to b4 any+ move from Pb2 to b3 {Pb3 Pb4 Pb5}) }

CQL 3.2
; In the caterpillar theme, tripled pawns creep up the board one pawn at a time (match :pgn heijden.pgn :output caterpillar.pgn (position Pb2 Pb3 Pb4 :movefrom Pb4 :moveto .b5 :gappedsequence ((position Pb3 Pb4 Pb5)) :flipcolor :shift ) )
After executing this with "> cql Caterpillar.cql" there are 136 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 5 studies are presented: