anchor.diff:             SY(K)=F
              IF (DABS(F).GE.1.0D+300) GO TO 20
              F0=F1
  -15         F1=F
  +           F1=F
  +15      END DO
   20      NM=K-1
           DO 25 K=1,NM
  -25         DY(K)=SY(K-1)-(K+1.0D0)*SY(K)/X
  +           DY(K)=SY(K-1)-(K+1.0D0)*SY(K)/X
  +25      END DO
           RETURN
           END SUBROUTINE
   
  
positive.code:         IF (DABS(X).LT.1.0D-100) THEN
             DO 10 K=0,N
                SJ(K)=0.0D0
  10            DJ(K)=0.0D0
             SJ(0)=1.0D0
             IF (N.GT.0) THEN
                DJ(1)=.3333333333333333D0
  
negative.code:            N0=N1
             F0=F1
             N1=NN
             F1=F
  10      END DO
  20      MSTA2=NN+10
          RETURN
          END FUNCTION
  