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