anchor.diff:    !               scalars 21 len(colno)  22 nstop     23 stage
     !                       24 neqns       25 len(iv) 26 len(dsln)
     !                       27 total
  -  !
     !        stage   10  after initialization
     !                20  building up matrix
     !                30  after LU decomposition
  
positive.code:     IMPLICIT NONE
      !------
      INTEGER, INTENT(IN):: Ndeg
      DOUBLE PRECISION, INTENT(IN):: A(Ndeg,*)
      DOUBLE PRECISION, INTENT(IN):: B(Ndeg,Ndeg,*)
      DOUBLE PRECISION, INTENT(OUT):: Wi(Ndeg)
      INTEGER, INTENT(INOUT):: N
      !------
      INTEGER:: jj
  
negative.code:     INTEGER:: lc
      INTEGER:: lc1
      INTEGER:: m
  
      l = 1
      ik = 0
  