Copyright Digital Equipment Corp. All rights reserved.

Return_Values

   x                  The relevant Bessel value of x of the second
                      kind.
   -HUGE_VAL          The x argument is 0.0; errno is set to ERANGE.
   NaN                The x argument is negative or NaN; errno is
                      set to EDOM.
   0                  Underflow occurred; errno is set to ERANGE.
   HUGE_VAL           Overflow occurred; errno is set to ERANGE.