<HTML ><HEAD ><TITLE >gmp_prob_prime</TITLE ><META NAME="GENERATOR" CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK REL="HOME" TITLE="Manual de PHP" HREF="index.html"><LINK REL="UP" TITLE="GMP functions" HREF="ref.gmp.html"><LINK REL="PREVIOUS" TITLE="gmp_powm" HREF="function.gmp-powm.html"><LINK REL="NEXT" TITLE="gmp_random" HREF="function.gmp-random.html"><META HTTP-EQUIV="Content-type" CONTENT="text/html; charset=ISO-8859-1"></HEAD ><BODY CLASS="refentry" BGCOLOR="#FFFFFF" TEXT="#000000" LINK="#0000FF" VLINK="#840084" ALINK="#0000FF" ><DIV CLASS="NAVHEADER" ><TABLE SUMMARY="Header navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TH COLSPAN="3" ALIGN="center" >Manual de PHP</TH ></TR ><TR ><TD WIDTH="10%" ALIGN="left" VALIGN="bottom" ><A HREF="function.gmp-powm.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="80%" ALIGN="center" VALIGN="bottom" ></TD ><TD WIDTH="10%" ALIGN="right" VALIGN="bottom" ><A HREF="function.gmp-random.html" ACCESSKEY="N" >Siguiente</A ></TD ></TR ></TABLE ><HR ALIGN="LEFT" WIDTH="100%"></DIV ><H1 ><A NAME="function.gmp-prob-prime" ></A >gmp_prob_prime</H1 ><DIV CLASS="refnamediv" ><A NAME="AEN23237" ></A ><P > (PHP 4 >= 4.0.4)</P >gmp_prob_prime -- Check if number is "probably prime"</DIV ><DIV CLASS="refsect1" ><A NAME="AEN23240" ></A ><H2 >Description</H2 >int <B CLASS="methodname" >gmp_prob_prime</B > ( resource a [, int reps])<BR ></BR ><P > If this function returns 0, <TT CLASS="parameter" ><I >a</I ></TT > is definitely not prime. If it returns 1, then <TT CLASS="parameter" ><I >a</I ></TT > is "probably" prime. If it returns 2, then <TT CLASS="parameter" ><I >a</I ></TT > is surely prime. Reasonable values of <TT CLASS="parameter" ><I >reps</I ></TT > vary from 5 to 10 (default being 10); a higher value lowers the probability for a non-prime to pass as a "probable" prime. </P ><P > The function uses Miller-Rabin's probabilistic test. </P ></DIV ><DIV CLASS="NAVFOOTER" ><HR ALIGN="LEFT" WIDTH="100%"><TABLE SUMMARY="Footer navigation table" WIDTH="100%" BORDER="0" CELLPADDING="0" CELLSPACING="0" ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" ><A HREF="function.gmp-powm.html" ACCESSKEY="P" >Anterior</A ></TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="index.html" ACCESSKEY="H" >Inicio</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" ><A HREF="function.gmp-random.html" ACCESSKEY="N" >Siguiente</A ></TD ></TR ><TR ><TD WIDTH="33%" ALIGN="left" VALIGN="top" >gmp_powm</TD ><TD WIDTH="34%" ALIGN="center" VALIGN="top" ><A HREF="ref.gmp.html" ACCESSKEY="U" >Subir</A ></TD ><TD WIDTH="33%" ALIGN="right" VALIGN="top" >gmp_random</TD ></TR ></TABLE ></DIV ></BODY ></HTML >