Asymptotic stability^335The usual trick amounts to eliminating yJ+^1 /^2 from (8) so as to reduce the
governing difference equations to the following ones:As a corollary to this fact, we see that(10)Having substituted into (10) the identity of artificial characteryj+1 -yj
yj+1 = yj + T ----
Tor y = y + T Yt, we recast the scheme at hand as
(11)The accurate account of the approximation error of scheme (11) on a
solution u = u(x, t) to equation (1) can be done using
(12)Upon substituting into (12) the expansionsu u -2-+ u -'rut -2- = '1l _ - 2 r (Ju -(}-t + O( T 2) 1
h2
Au= Lu+ l2 L^2 u + O(h^4 ),