// Download zugzwang2.cql
// PGN output when run on sample.pgn

This example is based on zugzwang1.cql, the same position occurs with
black to move in the mainline, but white to move in the variation, in
a win study.  However, this also requires that the paths from the
latest common ancestor to the two positions have a sequence of at
least 5 moves in common the output is sorted by the length of the
common sequence of moves. The position must arise from a white try.

cql(input hhdbvi.pgn result 1-0 variations)
 mainline btm
sort "Common consecutive move sequence"
 echo (source target){
  wtm try
  consecutivemoves (source target)5