perl -Mre=eval -nE <<CODE
chomp;
$_ = <<RULE . "---\n$_";
+ ^'>'+ ^
+ ^> ^
. ^`>`.. ^
. ^S>S ^
. ^K>K ^
. ^x>x+ ^

- ^'>- ^
- ^> ^
! ^`>!! ^
! ^S> ^
! ^K> ^
! ^x>- ^

, ; ^'>', '; ^
, ; ^>  ^
@ * ^`>`@@ `** ^
@ * ^S>S S ^
@ * ^K>K K ^
@ * ^x>x, x; ^

^>

```S>``.@`.*^
``K>.!^
RULE

BEGIN {
    my $vs = qr/[^ >\n]*/;
    my $ss = qr/ *?/;
    my $c_rule = qr/(?>($vs)$ss($vs)$ss($vs)$ss>$ss($vs)$ss($vs)$ss($vs)$)/m;
    my $nc_rule = qr/(?>(?:$vs$ss){3}>(?:$ss$vs){3}$)/m;
}
1 while
    s/$c_rule(?:\n+$nc_rule)*\n---\n.*?\K\1(.*?)\2(.*?)\3/$4$7$5$8$6/;
say ( ( split /\n/ )[-1] );
CODE