ABSTRACT
The equations we shall study in this chapter are all particular cases of the general system
∂u1 ∂t
∂u2 ∂t ...
∂um ∂t
=
D1 0 0 · · · 0 0 0 D2 0 · · · 0 0 ...
... ... · · · 0 0
0 0 0 · · · Dm−1 0 0 0 0 · · · 0 Dm
∇2u1 ∇2u2 ...
