Approximation theorems with \(A\)-convergence (Q1366753)

The author studies here sequences of linear operators which are `almost positive'. He gives Bohman-Korovkin type theorems for convergence for sequences of these operators in some \(A\)-norm that he introduced. He also studies the concept of a test family of functions on compact Hausdorff spaces and gives several results involving sequences of linear and sublinear operators.