anchor.diff:  C       Purpose: Compute the incomplete beta function Ix(a,b)
   C       Input :  a --- Parameter
   C                b --- Parameter
  -C                x --- Argument ( 0  x  1 )
  +C                x --- Argument ( 0 ≤ x ≤ 1 )
   C       Output:  BIX --- Ix(a,b)
   C       Routine called: BETA for computing beta function B(p,q)
   C       ========================================================
  
positive.code: C       =======================================================
  C       Purpose: Compute Bessel functions J0(x), J1(x), Y0(x),
  C                Y1(x), and their derivatives
  C       Input :  x   --- Argument of Jn(x) & Yn(x) ( x  0 )
  C       Output:  BJ0 --- J0(x)
  C                DJ0 --- J0'(x)
  C                BJ1 --- J1(x)
  
negative.code: C       ==========================================================
  C       Purpose: Compute Bessel functions Jn(x) & Yn(x) and
  C                their derivatives
  C       Input :  x --- Argument of Jn(x) & Yn(x)  ( x ≥ 0 )
  C                n --- Order of Jn(x) & Yn(x)
  C       Output:  BJ(n) --- Jn(x)
  C                DJ(n) --- Jn'(x)
  