title: Exact terminology of types in Scheme
body: <p>I am looking for a standard doc about types of Scheme. For instance, As types don't need to be explicitly specified in a program, I do not know it is <code>bool</code> or <code>boolean</code>; <code>LIST</code> or <code>LISTE</code>; <code>int</code> or <code>Nat</code>; <code>List[]</code> or <code>List[alpha]</code>...</p>
  
  <p>Another small question is how "atomic expression" is defined. For instance, is <code>'(1 2 3)</code> an atomic expression?</p>