anchor.diff:           case(3)
   c  + D is added to SOURCE in an explicit formulation . . .
   C-----------------------------------------------------------------------
  -  303    Do  I = I1, IN
  +  303    Do I = I1, IN
               SOURCE(I) = SOURCE(I) + DT*LO(I)*D(I)
            End do
         Return
  
positive.code: c     Correct the transported fluxes completely and then calculate the
  c     new Flux-Corrected Transport densities . . .
  C-----------------------------------------------------------------------
            FLXH(I1) = FSGN(I1) * AMAX1 ( 0.0,
       &                  AMIN1 ( TERM(I1), FABS(I1), TERP(I1) ) )
  
            Do I = I1, IN
               FLXH(I+1) = FSGN(I+1) * AMAX1 ( 0.0,
       &                AMIN1 ( TERM(I+1), FABS(I+1), TERP(I+1) ) )
               RHON(I) = RLN(I) * ( LNRHOT(I) + (FLXH(I) - FLXH(I+1)) )
               SOURCE(I) = 0.0
            End do
  
negative.code: 
        Block Data FCTBLK
  
            Implicit  None
            Integer,Parameter :: NPT = 202
  
  