title: How to set type of a property in Typescript as a combination of two ENUMs?
body: <p>I have one enum:</p>
  
  <pre class="lang-js prettyprint-override"><code>enum EAlphabet = {
      A = 'A',
      B = 'B',
      C = 'C',
      D = 'D',
      E = 'E',
      F = 'F',
      G = 'G',
      H = 'H',
      I = 'I',
      J = 'J',
      K = 'K',
      L = 'L',
      M = 'M',
      N = 'N',
      O = 'O',
      P = 'P',
      Q = 'Q',
      R = 'R',
      S = 'S',
      T = 'T',
      U = 'U',
      V = 'V',
      W = 'W',
      X = 'X',
      Y = 'Y',
      Z = 'Z'
  }
  </code></pre>
  
  <p>I have an interface I want to give the property of it the type that defines the following: that it can be either 'A', 'X', 'D', or it can be 'AA', 'JB', 'ZE', or it can be 'ABC', 'ZJE'.</p>
  
  <p>I'm not sure how to define it, but it would be something like this?</p>
  
  <pre class="lang-js prettyprint-override"><code>interface foo {
      bar: EAlphabet + EAlphabet? + EAlphabet? /* What to do here? */
  }
  </code></pre>