












• 
Each possible
joint configuration of the visible




and hidden units
has an energy




– 
The energy is determined by the weights
and



biases
(as in a Hopfield net).



• 
The energy of a
joint configuration of the visible



and hidden units
determines its probability:



• 
The probability
of a configuration over the visible


units is found
by summing the probabilities of all



the joint
configurations that contain it.

