In the last post, I explored different ways to model the *logic* of a **full-adder**. In this post I’ll explore a model of a *physical instance* of a full-adder — a model that *simulates* physical reality.

Because a full-adder is, at root, a mathematical expression, various software models can accomplish the same results. Models are abstractions, so the only thing a model can simulate *perfectly* is another model.