Chainsaw Sword

At Dragon 410, there is a magic item called the Chainsaw Sword. It is a interesting, but risky weapon. And one of my players show interest on it.

My problem comes with the two passive properties this weapon has. Against undead, it deals +1[w] damage, and against constructs it deal half damage. So, I added the following effects to the combat tracker, each line is one effect:

IFT: TYPE (undead); DMGW:1
IFT: TYPE (construct); Weakened

The first line works wonders. I dropped some undeads on the combat tracker for testing, and all of them were taking the extra damage. However, it was not true with the constructs. Did I wrote something wrong? You can't check for TYPE twice, even in separate lines? Weakened is the wrong effect to put there?

Yes I have also played with the chainsaw sword. the damage capacity of this sword is perfectly designed as up to game effect are concerned.

I'm afraid not every effect is transferable into FG. As 4e is an exception based rules system there are bound to be any number of things you can't program into effect lines. In the end you'll have to tell the player that the thing is a construct, have them roll the damage (without target), ricght click the damage line in the chat window and select 1/2, so the damage is halved, then drag and drop that damage line onto the construct. Or at least that's how I'd do it until a better solution comes along.