anchor.diff:  C CONDUCT TRACKING WITHIN ELEMENT M
   C
   C MWF REMOVE MAXPATH, KPATH ARGS
  -        CALL ELTRAK123A
  +        CALL ELTRAK123ANEW
        I      (MAXEQ,MAXND,NPT,NEQ,NODE,
        I       IPT, T1,T2, DEQ, DN_SAFE,
        I       ZEROTOL,IDVT,
  
positive.code: C     HAVE TO TREAT AS FLAT ARRAY, SINCE MAY BE DIFFERENT SHAPES IN PYTHON (q, versus ebqe)
  C     ASSUME MPT,TPT SET BY CALLING CODE 
  CMWF DEBUG
  C      WRITE(LU_O,*)'ENTERING PT123A'
  C      WRITE(LU_O,*)'NNP= ',NNP,' NEL= ',NEL,' NNDE= ',NNDE,' NEQ= ',NEQ,
  C     &     ' NPT= ',NPT,' IBF= ',IBF,' LU_O= ',LU_O, ' ATOL= ',ATOL,
  C     &     ' RTOL= ',RTOL, ' SF= ',SF, 'DN_SAFE= ',DN_SAFE
  
        DO IPT=1,NPT
  CMWF DEBUG
  C         WRITE(LU_O,*)'T_I(',IPT,')= ',T_I(IPT),
  C     &        ' TPT(',IPT,')= ',TPT(IPT)
           DO I=1,NEQ
              XS(I)=X_I(I + MAXEQ*(IPT-1))
              XPT(I + MAXEQ*(IPT-1))=XS(I)
  CMWF DEBUG
  C            WRITE(LU_O,*)'X_I(',I,',',IPT,')= ',X_I(I+MAXEQ*(IPT-1)),
  C     &           ' XPT(',I,',',IPT,')= ',XPT(I + MAXEQ*(IPT-1))
  
          ENDDO
        ENDDO
  C
  C =================== START PT USING ADAPTIVE RK ====================
  
negative.code:      M       DN_S,DN,DDN,
       O       IDSDT,XPT,TPT,I1,I2,I3)
  CMWF        NPATH(IPT)=KPATH
          IF(IVERBOSE.GT.1) THEN
  C MWF DEBUG
             WRITE(LU_O,*)' AFTER ELTRACK ELEMENT LOOP T= ',T,
       &          ' IDSDT= ',IDSDT,' TPT= ',TPT(IPT),' IPT= ',IPT,' M= ',M
             WRITE(LU_O,*)' I1= ',I1,' I2= ',I2,' I3= ',I3
             DO K=1,NEQ
                WRITE(LU_O,*)' XPT(',K,',',IPT,')= ',XPT(K+(IPT-1)*MAXEQ)
             ENDDO
          ENDIF
  C
          IF(IDSDT.EQ.-1)THEN
            MPT(IPT)=M
  