enpassantecho.cql

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

/*******
Two positions differ only in whether en passant is legal
**********/

cql(input heijden.pgn variations )
   move enpassant
   echo (source target){
     sidetomove==source:sidetomove
     not move legal enpassant
     source&target==.
     }