chapter  1
16 Pages

Formulation of the Problems

Throughout what follows, a superscript t denotes matrix transpo­ sition, Greek and Latin subscripts take the values 1, 2 and 1, 2, 3, respectively, and, unless otherwise stipulated, the convention of sum­ mation over repeated indices is understood. For the sake of simplic­ ity, we use no special symbols to distinguish between vector-valued and scalar functions, nor between spaces of such functions, the mean­ ing of the notation being clear from the context.