text: const addToDom = (elementId) => { return document.querySelector(`#${elementId}`)}
  
  const h1 = (message) => `<h1>${message}</h1>`
  const echo = message => message;
  
  // -run- with two functions 
  var run2 = function(f, g) {
    return function(x) {
        return f(g(x));
    };
  };
  
  // -run- with three functions
  var run3 = function(f, g, h) {
    return function(x) {
          return f(g(h(x))); 
    };
  };
  
  var printMessage = run3(addToDom('msg'), h1, echo);
  
  printMessage('Hello World');