In relation to the famous problem of Ulam ``Give conditions in order for a linear mapping near an approximated linear mapping to exist'', we consider the stability or superstability of generalized linear equation f(x+y)−f(x)−f(y)=B[ϕ(x)+ϕ(y)]f(x+y)-f(x)-f(y)=B[\phi(x)+\phi(y)] by left or right perturbations with some hypotheses of convexity or concavity, and – in a forthcoming paper – apply our conclusions to the generalized exponential equation f(x+y)f(x)f(y)=[ϕ(x)ϕ(y)]B.\frac{f(x+y)} {f(x)f(y)}= [\phi(x)\phi(y)]^{B}.

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C. Peppo. “Asymptotic Hyers-Ulam Stability or Superstability for Generalized Linear Equations by Unilateral Perturbations.” Journal of Convex Analysis 26 (2019), No. 2, 543–562. https://doi.org/10.68381/jca26028