anchor.diff:             HU=X**(-A)*HU
              ID=10
           ELSE
  +C       DLMF 13.7.3
              HU=1.0D0
              R=1.0D0
              DO 15 K=1,25
  
positive.code:         NM=0
          IF (IL1) NM=ABS(A)
          IF (IL2) NM=ABS(AA)
          IF (IL1.OR.IL2) THEN
             HU=1.0D0
             R=1.0D0
  
negative.code:               HU=HU1
             ENDIF
          ENDIF
          IF (A.GE.1.0) THEN
             IF (BN.AND.(BL1.OR.BL2.OR.BL3)) THEN
                CALL CHGUBI(A,B,X,HU,ID)
                MD=3
  