anchor.diff:        IF (IMPSPECIES .EQ. -1) THEN
            TARGETCONC = -1E10
            IMPSPECIES = 1
  +         conc = -1
         END IF
   
    1    IF (Time .LE. TOUT .AND. Y(IMPSPECIES) .GE. TARGETCONC*Y(NSTATE))
  
positive.code: 
  
        INTEGER  INFO(30), LIW, LRW, IWORK(*), IPAR(1),IDID, iter,
       $     IMPSPECIES
        DOUBLE PRECISION Y(NSTATE), YPRIME(NSTATE), Time, TOUT, RTOL, ATOL
       $     , RWORK(*), TARGETCONC
  
  
negative.code:                PREVREACTIONFLUX(I) = CURRENTREACTIONFLUX(I)
              END DO
              PREVTIME = TIME
              if (conc .eq. 1) then
                 tout = 200*time
              end if
  c            write(*,*) time, y(impspecies), targetConc*y(nstate)
              GO TO 1
           END IF
  