title: Is adding a dimension broadcasting?
body: <p>Given</p>
  
  <pre><code>a = tf.constant([[1, 2, 3], [10, 20, 30], [100, 200, 300], [1000, 2000, 3000]])
  </code></pre>
  
  <p>all of the following are equivalent</p>
  
  <pre><code>b = tf.constant([100000, 200000, 300000])
  print((a+b).eval())
  
  bb = tf.constant([[100000, 200000, 300000]])
  print((a+bb).eval())
  
  bbb = tf.constant([[100000, 200000, 300000], [100000, 200000, 300000], [100000, 200000, 300000], [100000, 200000, 300000]])
  print((a+bbb).eval())
  </code></pre>
  
  <p>and produce</p>
  
  <pre><code>[[100001 200002 300003]
   [100010 200020 300030]
   [100100 200200 300300]
   [101000 202000 303000]]
  </code></pre>
  
  <p>I understand that <code>bb</code> is "broadcast" to the value corresponding to <code>bbb</code> by <code>tf.add</code> (here <code>+</code>). Is the addition of a dimension that transforms <code>b</code> to the value of <code>bbb</code> all broadcasting, or is it something else?</p>