Binary decision diagram

1. Decide order of variables
2. Create truth table
3. Create tree from truth table
4. Merge equivalent leaves - We want two leaves, [ 1 ] and [ 0 ]. Redirect all edges from the removed nodes to the equivalent leave
5. Merge isomorphic nodes - Remove all nodes that have the same variable and identical children as another node. Redirect all edges that went into the redundant node into the one copy that you kept
6. Eliminate redundant tests - Remove all nodes that has the same child twice. Redirect all edges into redundant node into the child node
7. Repeat steps 4 5 6 until no more improvements can be made

We now have a canonical reduced ordered binary decision diagram. All nodes now represents different functions that all are canonical.

Problem: This procedure becomes impossible with many variables.

Solution: Build the reduced tree directly from the boolean expression.

How: To be determined...

1. Recursively walk the circuit gate by gate from the input to the output and perform each operation on the BDD tree.