const numbers = [1, 2, 3, 4, 5, 6];

const result = numbers
  .map(x => x * 2)
  .filter(x => x > 6)
  .reduce((acc, x) => {
    console.log(`Processing ${x}, acc: ${acc}`);
    return acc + x;
  }, 0);

console.log(`Final result: ${result}`);