Using the concepts of a semi
inner-product and a dissipative operator, it is proven that if X is a complex Banach
space (under the supremum norm) of bounded complex valued functions on a set S, p
is a bounded positive function on S which is bounded away from zero, pX ⊂ X, and
A is the infinitesimal generator of a strongly continuous (class (C0)) semi-group of
contraction operators in X, then pA is also the infinitesimal generator of such a
semi-group.