= THE  VALUE</span>
<span class="c">!                                OF THE TAIL LENGTH PARAMETER.</span>
<span class="c">!                                ALAMBA SHOULD BE POSITIVE.</span>
<span class="c">!     OUTPUT ARGUMENTS--PPF    = THE  PERCENT</span>
<span class="c">!                                POINT FUNCTION VALUE.</span>
<span class="c">!     OUTPUT--THE  PERCENT POINT  .</span>
<span class="c">!             FUNCTION VALUE PPF</span>
<span class="c">!             FOR THE POISSON DISTRIBUTION</s