624 Eco1101nical Differeuce Schemes for Multidimensional Problems
Also, the operator A will be taken to be
(52)
where linear operators Aa are so chosen as to provide the relation
p
n D(Aa) = D(A),
a:=:I
making it possible to reduce the solution of the Cauchy problem (51) to
solving successively the Cauchy problems of the same type, but with oper-
ators Aa standing in place of the operator A. We confine ourselves here to
two possible ways of such a reduction.
For later use, it will be sensible to introduce on the segn1ent 0 < t < t 0
a grid w 7 = {tj = jr, j 0, 1, ... ,j 0 } with step T and to atten1pt the
function f in the form
p
f = 2= fa.
The first reduction (for more detail see Section 3). The object of
investigation is a chain of the equations
(53) et=l,2, ... ,p,
with the supplementary initial conditions
(54) j=l,2,. .. ,
j=O,l, .. ., et=2,3, ... ,p.
The function v(tj+i) = v(p)(tj+i) refers to a solution of this problen1
fort= tj+J · In the general case we might have
for all j = 1,2, ...