Help me identify a tree and a possible disease? I have a tree that have leaves sort of like a...

I have a tree that have leaves sort of like a maple (I live within Ontario) but it has smaller quantity points - 3 per leaf - and the leaves are narrower, irregular edges and opposite respectively other on the branches.

The tree has developed an oilish spotting on the trunk and I am concerned. I didn't distinguish this just a few days ago when I be planting flowers. Does anyone know what kind of tree it is and what this slimy spotting might be?
A pool beside dimensions of 25metrx x 25...
Answers:    Without a picture it is hard to identity a tree for you. As for the slimy spot I would contact an arborist and they probably tell you over the phone what the problem is.
What can I do to produce my neighbour...