equation of the form∑ i= 1 m A i (f φ i (x¯))= D (x¯) for all x¯∈ X n, where f is the unknown
mapping from a linear space X over a field K∈{R, C} into a linear space Y over field K; n and
m are positive integers; φ 1,…, φ m are linear mappings from X n to X; A 1,…, A m are
continuous endomorphisms of Y; and D: X n→ Y is fixed. In this paper, the stability inequality
is considered with regard to a convex modular on Y, which is lower semicontinuous and …