while (my $line=<$tfh>) {
    chomp $line;
    my ($id, $title, $abs)=split /\|/, $line;
    my @sentences=split /\./, $abs;
    print $ofh "$id|";

    for my $idx (0..$#sentences) {
        print $ofh '<', $idx+1, '>';
        for my $word (split ' ', $sentences[$idx]) {
            if ($words{uc $word}) {
                print $ofh "$word "
            }
            else {
                for (sort keys %words) {
                    if ($words{$_}{uc $word}) { 
                        print $ofh "mainterm:$_:matchedterm:$word ";
                        last; 
                    }
                }
            }
        }
    }
    print $ofh "\n";
}