The more complex the logic the more likely it is to not work in the dream world. The only one which is consistently reliable for me is simple predication "x is y", "I am b", etc... You can even redefine things right in front of you "that tree is a door" works surprisingly well. I never see things "change" from one to another, it actually more like I was previously mistaken and it has always been what I said it is.

Another thing that works well in dreams are metaphor, analogy, and puns. I once saved a damsel in distress from a burning building by "fighting fire with the fire of passion"... yeah... awesome dream.

Hard logic is tough tough. It seems mostly inaccessible to me in my dreams. However, there is an entire suite of thought processes which I would call "dream logic".