title: How do I subtract two "numbers" in LC3?
body: <pre><code>LD  R0, NUM1
  NOT R0, R0
  ADD R0, R0, #1
  LD  R1, NUM2
  ADD R1, R0, R1
  OUT
  BRn BIG
  </code></pre>
  
  <p>Hi, I am trying to compare NUM1 with NUM2. Assume NUM1 is less than NUM2, then my R1 should be a negative number. My current algorithm is not working, and I want to branch out if I get a negative number. Any help would be appreciated!</p>