anchor.diff:  
   C----------COMMON AREAS.
         COMMON /compr/  cy,ct,t9i,t9f,ytmin,inc        !Computation parameters.
  -      COMMON /lncoef/ a,b_,y                          !Lin eqn coefficients. 
  +      COMMON /lncoef/ a,bkevin,y                     !Lin eqn coefficients. 
         COMMON /flags/  ltime,is,ip,it,mbad            !Flags, counters.
         COMMON /runopt/ irun,isize,jsize               !Run options.
   
  
positive.code:                   DO k = 1,isize
                      r = r + a0(j,k)*y(k) !Left side with approximate solution.
                    END DO
                    x(j) = b(j) - r  !Subtract difference from right side.
                  END DO
  C..........OPERATE ON RIGHT-HAND VECTOR.
                  DO j = 1,isize-1
  
negative.code: 
  C----------MATRIX COEFFICIENTS FOR LINEAR EQUATION.
        DOUBLE PRECISION a(nnuc,nnuc)!Coefficient array.
        REAL    bkevin(nnuc)         !Right-hand vector w/o manipulation.
        REAL    y(nnuc)              !Solution vector.
  
  C----------COUNTERS AND FLAGS.
  