Let be the set of real Analytic Functions on .
Then is a
Subalgebra of . A Necessary and Sufficient condition for a function
to belong to is that

for , 1, ... for a suitable constant .

**References**

Iyanaga, S. and Kawada, Y. (Eds.). *Encyclopedic Dictionary of Mathematics.* Cambridge, MA: MIT Press, p. 207, 1980.

© 1996-9

1999-05-26