#### Polytree

- (1) singly connected, (2) no loops, (3) at most one path between any two nodes
- Efficient algorithms for exact inference

#### Process

#### Notes

- Termination
- Root node does not have parents, so probability will be given.
- Leaf node does not have children, so no recursive call can happen down stream.
- Computing Evidence node’s probability is trivial, because it can be done by recursive call of marginalization. (Trivial)

- Runtime analysis
- Linear in number of nodes and in size of CPTs.

- Problem solving in general
- Start off with
**Bayes rule**if the order is wierd,**Product rule**to remove something,**Marginalization**if something is missing…

- Start off with

#### Reference