title: Formal logic sentence for nested if/else
body: <p>If I want to write sentence "if A then B else C" in formal logic, I can:</p>
  
  <pre><code>(A -&gt; B)  V  (~A -&gt; C)
  </code></pre>
  
  <p>How can I write the same in this form (I don't remember how was called this form like "rational"):</p>
  
  <pre><code>A -&gt; B ???
  ----------
    C ???
  </code></pre>
  
  <p>Real question is: I have many nested "if .. else" and second form seems more natural to write such nested if's. I can write nested "if.. else" if first form, but I don't know how to write them in second, because I don't know how to write single "if.. ELSE" in the second form (due to "else" clause). Is it possible even?</p>