c &amp;opt capacity)</code> to create a new thread. This thread
will start and wait for a message containing a function that it will run as the
main body. This function must also be able to take 1 parameter, the parent
thread.  Each thread has its own mailbox, which can asynchronously receive
messages. These messages are added to a queue, which has a configurable maximum
capacity according to the second optional argument passed to <code class="mendoza-code">thread/new</code>.
If unspecified, the mailbox wil