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author | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2020-11-23 19:29:14 +0100 |
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committer | Marco Bodrato <bodrato@mail.dm.unipi.it> | 2020-11-23 19:29:14 +0100 |
commit | c35873501420a452152260a8d013e0ac47fbaf15 (patch) | |
tree | cddb394cc52d2eaf04d052a67adc0d0e263641c0 /doc/gmp.texi | |
parent | fa7469a0dace657f461c352fd029788de9e1148c (diff) | |
download | gmp-c35873501420a452152260a8d013e0ac47fbaf15.tar.gz |
doc/gmp.texi: Document mpz_prevprime (by Troisi)
Diffstat (limited to 'doc/gmp.texi')
-rw-r--r-- | doc/gmp.texi | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/doc/gmp.texi b/doc/gmp.texi index 6bca5da75..70672f34a 100644 --- a/doc/gmp.texi +++ b/doc/gmp.texi @@ -3563,8 +3563,19 @@ primality test. In those older versions of GMP, this function performed @deftypefun void mpz_nextprime (mpz_t @var{rop}, const mpz_t @var{op}) @cindex Next prime function Set @var{rop} to the next prime greater than @var{op}. +@end deftypefun + +@deftypefun int mpz_prevprime (mpz_t @var{rop}, const mpz_t @var{op}) +@cindex Previous prime function +Set @var{rop} to the greatest prime less than @var{op}. + +If a previous prime doesn't exist (i.e. @var{op} < 3), rop is unchanged and +0 is returned. + +Return 1 if @var{rop} is a probably prime, and 2 if @var{rop} is definitely +prime. -This function uses a probabilistic algorithm to identify primes. For +These functions use a probabilistic algorithm to identify primes. For practical purposes it's adequate, the chance of a composite passing will be extremely small. @end deftypefun |