It never lasts long enough to get complex, it appears in a virtual functional&#x2F;anti-functional pair and then they annihilate each other.<p>Only in the presence of a powerful gravitational force, like the edge of a corporate programming style guide, will one of the pair be sucked into the maw, leaving the other to accumulate cruft.<p>For example, the second can incorporate two-way binding as noted, logging, synchronization via Operational Transforms, and so much more...