doc: tweak factor-describing wording

* doc/coreutils.texi (factor invocation): Don't say that "factoring
large prime numbers is hard".  A pedant might ding you, since it's
trivial to factor a number that is known to be prime.  Instead, say
that "factoring large numbers... is hard".  Reported by Andreas Eder.

diff --git a/doc/coreutils.texi b/doc/coreutils.texi
index f40993e..73971c6 100644 (file)
--- a/doc/coreutils.texi
+++ b/doc/coreutils.texi
@@ -15470,7 +15470,7 @@ M8=`echo 2^31-1|bc` ; M9=`echo 2^61-1|bc`
 Similarly, factoring the eighth Fermat number @math{2^{256}+1} takes
 about 20 seconds on the same machine.
 
-Factoring large prime numbers is, in general, hard.  The Pollard Rho
+Factoring large numbers is, in general, hard.  The Pollard Rho
 algorithm used by @command{factor} is particularly effective for
 numbers with relatively small factors.  If you wish to factor large
 numbers which do not have small factors (for example, numbers which