There's something... not quite right about loopy. I think it's just that it has inverters but not diodes?
You can see for example if you try to form an ecosystem with a Sun node feeding one or more plant nodes that feed herbivore nodes that feed carnivore nodes, with Death nodes that kill off living things.
Eventually once the thing is running smoothly you can just turn off the sun and turn up the death and somehow those plants will still be thriving, apparently because the death of the herbivores is the same as sunshine to the plants.
This means that loopy seems to have real trouble with describing dynamic equilibrium states...
