## Abstract

A well known result of R. R. Phelps (1960) asserts that in order that every linear continuous functional, defined on a subspace \(Y\) of a real normed space \(X\), have a unique norm preserving extension it is necessary and sufficient that its annihilator \(Y^{\perp}\) be a Chebyshevian subspace of \(X\ast\). The aim of this note is to show that this result holds also in the case of spaces with asymmetric norm.

## Authors

**Costica Mustăţa**

“Tiberiu Popoviciu” Institute of Numerical Analysis, Romanian Academ, Romania

## Keywords

Asymmetric normed spaces; extensions preserving asymmetricnorm; best approximation

## Paper coordinates

C. Mustăţa, *On the uniqueness of extension and unique best approximation in the dual of an asymmetric normed linear space,* Rev. Anal. Numer. Theor. Approx. 32 (2003) no. 2, 187-192.

## About this paper

##### Journal

Revue d’Analyse Numerique et de Theorie de l’Approximation

##### Publisher Name

Publising Romanian Academy

##### DOI

##### Print ISSN

2457-6794

##### Online ISSN

2501-059X

google scholar link

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