Determining subspaces for discrete-type linear forms on commutative Banach algebras

In this paper we deal with some problems of the Korovkin-type Approximation theory concerning the convergence of nets of linear forms toward discrete-type linear forms on commutative Banach algebras. We also study the case of involutive symmetric commutative Banach algebras with identity or with bounded approximate identity. Examples and applications are presented in the context of the algebrasC ₀(X, C),C(X, C) andL ¹ (IR).