Low-scoring a troll and direct replies

[Teemu Likonen]

Let's say I want to low-score a certain Usenet troll as well as all
direct replies to troll's messages. I think I can do this with a this
kind of rule:

    ((| ("from" "Troll <troll@invalid>" s)
        (1- ("from" "Troll <troll@invalid>" s)))
     -1000)

But it doesn't seem to match always for replies. I believe that the
problem is when there are not any troll's posts among new messages, only
replies. Maybe the (1- ...) part doesn't check previously seen messages.

Is there a way to fix this?