Derivations for a class of matrix function algebras

We study a class of matrix function algebras, here denoted T⁺(C_n). We introduce a notion of point derivations, and classify the point derivations for certain finite dimensional representations of T⁺(C_n). We use point derivations and information about n×n matrices to show that every T⁺(C_n)-valued derivation on T⁺(C_n) is inner.