title: Why is deciding NP deterministically exponential time
body: <p>From a textbook, it says:</p>
  
  <blockquote>
    <p>The best deterministic method currently known for deciding languages in NP uses exponential time. In other words, we can prove that<br>
    <img src="https://i.imgur.com/jJQz7QU.png" alt=""><br>
    ... </p>
  </blockquote>
  
  <p>Why is this true? I can't seem to find the intuition for this. </p>