[Exim] complex conditionals?

I've checked the www.exim.org, and it doesn's say yay or nay about this.

Does the system filter mechanism support nested conditionals? I'd like to
set up something like this:

if conditionA then
    if conditionB then
        do something
        finish
    end
    if condition C then
        do something
        finish
    end
end

or

if conditionA then
    if conditionB then
        do something
        finish
     else if condition C then
        do something
        finish
    end
end

---
Dennis Taylor
---
Don't worry about people stealing your ideas. If your ideas
are any good,
you'll have to ram them down people's throats.