(Neptyne cofounder here)

That's probably something we should dig more into in the docs, yeah. Neptyne works like a ipython/Jupyter notebook in that everything is in scope all the time. So you can write your code in an imperative way (e.g. `B10 = some_value`) within a function, or you can do use a functional style.

We handle spreadsheet-style reactivity by building the dependency graph out of any cell addresses mentioned in the cell itself. So if you have `=my_func(A1)` in one cell, it will re-run when A1 changes. But if my_func reads from, say, B1, it will not automatically re-run when B1 changes.