Geodesic
On finite-dimension Chebyshev subspaces of spaces with an integral metric
Sbornik. Mathematics, Tome 74 (1993) no. 2, pp. 361-380 
N. K. Rakhmetov. On finite-dimension Chebyshev subspaces of spaces with an integral metric. Sbornik. Mathematics, Tome 74 (1993) no. 2, pp. 361-380. http://geodesic.mathdoc.fr/item/SM_1993_74_2_a4/
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     title = {On finite-dimension {Chebyshev} subspaces of spaces with an integral metric},
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Voir la notice de l'article provenant de la source Math-Net.Ru

This is a detailed study of the problem of the existence and characterization of finite-dimensional Chebyshev subspaces of the spaces $\varphi(L)$ and $L^{p(t)}$ on the interval $I=[-1,1]$, where $\varphi(t)$ is an even nonnegative continuous nondecreasing function on the half-line $[0,+\infty)$, and the function $p(t)$ is measurable, finite, and positive almost everywhere on $I$. If $\varphi$ is an $N$-function, it is characterized as a Chebyshev subspace of the Orlicz spaces with the Luxemburg norm.

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