BEGIN{
  Stem="tmp";
  IGNORECASE=1;
  Comments="%.*";
  FS=",";
}
                    { sub(Comments,"") }
/^[ \t]*$/          { next }
/@relation/         { Relation=$0 }
/@data/             { _data=1 } 
/@attribute/        { Attr[++A]=$0 }                
/@relation/,/@data/ { next }
_data               { Rows++;
                      Cols=NF;
                      for(Col=1;Col<=Cols;Col++) D[Rows,Col]=$Col;
                      next;
} 
                    { split($0,Words," ");
                      Ranks[Words[3]] = Words[3];
                      Rank[Words[1]]  = Words[3] 
}
END {  
  N=asort(Ranks)
  for(I=1;I<=N;I++) {
    delete Use;
    for(J=I;J<=N;J++) Use[Ranks[J]];
    #for(J in Use) print I " wants " J
    some(Use,Stem "_"  I ".arff");
  }
  delete Use;
  some(Use,Stem "_0.arff");
}
function some(want,f,   i,use,row,col,sep) {
  for(i=1;i<=Cols;i++)
    use[i] = Rank[i] in want;
  use[Cols] = use[Cols - 1] = 1;
  print Relation > f;
  for(i=1;i<=A;i++)
    if (use[i])
      print Attr[i] >> f;
  print "@data" >> f;
  for(row=1;row<=Rows;row++) {
    sep="";
    for(col=1;col<=Cols;col++)
      if (use[col]) {
        printf sep D[row,col]>>f;
        sep=","};
    print "" >>f; }
}