Complex analysis is very rich in approximation theory results. In this Preface we briefly list
some of them which are nowadays considered classical, with no pretense of completeness …

In recent years, much attention has been paid to the role of classical special functions of a
real or complex variable in mathematical physics, especially in boundary value problems …

In this paper, the hypercomplex Ruscheweyh derivative operator for special monogenic
functions is defined. The representation in certain regions of such functions in terms of …

Hypercomplex function theory generalizes the theory of holomorphic functions of one
complex variable by using Clifford Algebras and provides the fundamentals of Clifford …

This paper introduces a generalization of the Hasse derivative in the sense of the complex
conformable derivative. The definition coincides with the classical version of the Hasse …

Along with the theory of bases in function spaces, the existence of a basis is not always
guaranteed. The class of power series spaces contains many classical function spaces, and …

In this paper, we first provide some functional equations of the generating functions for beta-
type polynomials. Using these equations, we derive various identities of the beta-type …

The notion of the generalized Hadamard product of bases in Clifford analysis is introduced.
Certain convergence properties of such generalized Hadamard product bases in terms of …

Intensive research efforts have been dedicated to the extension and development of
essential aspects that resulted in the theory of one complex variable for higher-dimensional …

The main objective of this paper is to give a wide study on the conformable fractional
Legendre polynomials (CFLPs). This study is assumed to be a generalization and …