ul>

<p><strong>Parameters:</strong>
  <strong>possiblePrefix:</strong> A sequence to compare to this sequence.
  <strong>areEquivalent:</strong> A predicate that returns <code>true</code> if its two arguments
    are equivalent; otherwise, <code>false</code>.
<strong>Returns:</strong> <code>true</code> if the initial elements of the sequence are equivalent
  to the elements of <code>possiblePrefix</code>; otherwise, <code>false</code>. If
  <code>possiblePrefix</code> has no elements, the return value is <