anchor.diff:             ELSE
                 M=MSTA2(X,N,15)
              ENDIF
  +           F=0.0D0
              F0=0.0D0
              F1=1.0D0-100
              DO 15 K=M,0,-1
  
positive.code:         HU=R1-R2
          HMAX=0.0D0
          HMIN=1.0D+300
          DO 10 J=1,150
             R1=R1*(A+J-1.0D0)/(J*(B+J-1.0D0))*X
             R2=R2*(A-B+J)/(J*(1.0D0-B+J))*X
  
negative.code: C       ========================================================
  C
          IMPLICIT DOUBLE PRECISION (A-H,O-Z)
          W=0.0D0
          IF (KD.EQ.1.OR.KD.EQ.2) W=2.0D0*M+1.0D0
          IF (KD.EQ.3.OR.KD.EQ.4) W=2.0D0*M-1.0D0
          W2=W*W
  