Counter.jsx

import { initialize, split } from "apothecary";
import { tunnel, fromProps } from "react-apothecary";

const store = initialize({ n: 1 });

const increment = step => split(n => n + step, "n");

const decrement = step => split(n => n - step, "n");

...

const CounterApp = tunnel(
  (state, props) => {
    return { n: state.n + props.offset };
  }, {
    inc: increment(4),
    dec: decrement(4)
  }
)(Counter);