Dealing with missing inputs
The network learns the constraints even if 10% of the
inputs are missing.
First fill in the missing inputs randomly
Then use the back-propagated energy derivatives to
slowly change the filled-in values until they fit in with
the learned constraints.
Why don’t the corrupted inputs interfere with the  learning
of the constraints?
The energy function has a small slope when the
constraint is violated by a lot.
So when a constraint is violated by a lot it does not
adapt.
Don’t learn when things don’t make sense.