anchor.diff:  C
   C PYADH HAD               IF(DABS(D2).GT.DN_SAFE)THEN
   C                  CALL DN_CHECKA
  -C     I                 (MAXND,NODE,NEQ, 1.D0,DN_SAFE,
  +C     I                 (MAXND,NODE,NEQ, DL,ZEROTOL,
   C     I                 DN_S,
   C     O                 I1,I2,I3)
                  IF(DABS(D2*DL).GT.ZEROTOL)THEN
  
positive.code:      O                 I1,I2,I3)
                    IDSDT=0
  
                    IDSDT=0
                    IF (IDEBUG.GT.0) THEN
  C MWF DEBUG
                       WRITE(6,*)' ELTRAK DN_CHECKA LEAVING IDSDT= ',
  
negative.code: C ==> NO NEED TO REDUCE TIMESTEP
  C
  C PYADH HAD               IF(DABS(D2).LE.DN_SAFE) THEN
                 IF(DABS(D2).LE.DN_SAFE) THEN
  C LATER VERSION WAS
  C               IF(DABS(D2*DL).LE.ZEROTOL) THEN
                    IF (IDEBUG.GT.0) THEN
  C MWF DEBUG
                       WRITE(6,*)'D2*DL.LE.ZEROTOL GOTO 150'
  