tol</I> is a nonnegative input variable.  Termination occurs when
the algorithm estimates either that the relative error in the sum of
squares is at most <I>tol</I> or that the relative error between
<I>x</I> and the solution is at most <I>tol</I>.
<P>
<I>info</I> is an integer output variable. if the user has
terminated execution, <I>info</I> is set to the (negative)
value of iflag. see description of <I>fcn</I>. otherwise,
<I>info</I> is set as follows.
<P>
<BR>&nbsp;&nbsp;<I>info</I>&nbsp;=&nbsp;0&nbsp;&