Thanks for your reply.

I think you are right about the rules, just expressing them in a different way, not by local interaction between neighboring nodes, but by first-order logic!

When we add 2 (S(S(0))) and 3 (S(S(S(0)))).

I think we start with:

```

Add

| -- S -- S -- Z

| -- S -- S -- S -- Z

```

and then we would reduce it to:

```

S -- S -- S -- S -- S -- Z

```

At the top right corner of the homepage, there is a link to "Docs" -- https://readonly.link/articles/https://cdn.inet.cic.run/docs...

Maybe this article can help.