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Composing Power Series Over a Finite Ring in Essentially Linear Time

✍ Scribed by Daniel J. Bernstein


Publisher
Elsevier Science
Year
1998
Tongue
English
Weight
261 KB
Volume
26
Category
Article
ISSN
0747-7171

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✦ Synopsis


Fix a finite commutative ring R. Let u and v be power series over R, with v(0) = 0. This paper presents an algorithm that computes the first n terms of the composition u(v), given the first n terms of u and v, in n 1+o(1) ring operations. The algorithm is very fast in practice when R has small characteristic.