To track the n most likely trajectories
		For each new time step until the end of time
			Create full copy of the model for the new time step
			Assign command and observation variables
			Until n consistent trajectories found
				Enumerate the next best t-length trajectory
				Throw it out if inconsistent
			Report the t-length trajectories
	An Algorithm with Only Two Problems!
		Space  - Representation grows linearly with time
		Time   - Search space grows exponentially with time                          - Checks an exponential number of obviously wrong candidates
	The assignments to t capture every possible trajectory
	Trajectories can be enumerated in prior probability order
			P(trajectory) = S P(t assignment)
	Each trajectory can be checked for agreement with observations
	Avoid committing to a small number of trajectories
	Build a structure that compactly represents all evolutions
	Generate additional trajectories in order as needed