Figure from ROBOT, Moravec, Oxford, 1998, Chapter 6: The Age of Mind, page 184
time loop fixed point circuit

"Fixed point" finder

The "Next Approximation" circuit takes an approximate answer and produces a better one. Here, its output is connected to its input through delay-canceling negative time delays. If the whole circuit doesn't break, it is forced by a causal loop to snatch, instantly, out of thin air, a perfect solution that cannot be further refined.