How to interleave 10 and 9 (while also causing a stack overflow). Code only works in language that has function hoisting.

mutual-recursion.js

a(10, 1);

function a(n, steps) {
  console.log(n, steps);
  if (n == 1) {
    return 0;
  }
  return b(n - 1, steps+1);
}

function b(n, steps) {
  console.log(n, steps);
  if (n == 1) {
    return 0;
  }
  return a(n + 1, steps+1);
}