<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"
"http://www.w3.org/TR/REC-html40/loose.dtd">
<HTML>
<HEAD>
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<META name="GENERATOR" content="hevea 1.06-7 of 2001-11-14">
<TITLE>
Term unification
</TITLE>
</HEAD>
<BODY TEXT=black BGCOLOR=white>
<A HREF="manual024.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A>
<A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A>
<A HREF="manual026.html"><IMG SRC ="next_motif.gif" ALT="Next"></A>
<HR>
<TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%">
<TR><TD BGCOLOR="#66dbff"><DIV ALIGN=center><TABLE>
<TR><TD><FONT SIZE=4><B><A NAME="htoc68">7.2</A></B></FONT></TD>
<TD WIDTH="100%" ALIGN=center><FONT SIZE=4><B>Term unification</B></FONT></TD>
</TR></TABLE></DIV></TD>
</TR></TABLE><UL>
<LI><A HREF="manual025.html#toc45"> <TT>(=)/2</TT> - Prolog unification</A>
<LI><A HREF="manual025.html#toc46"> <TT>unify_with_occurs_check/2</TT></A>
<LI><A HREF="manual025.html#toc47"> <TT>(\=)/2</TT> - not Prolog unifiable</A>
</UL>
<BR>
<A NAME="toc45"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%">
<TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE>
<TR><TD><B><A NAME="htoc69">7.2.1</A></B></TD>
<TD WIDTH="100%" ALIGN=center><B><TT>(=)/2</TT> - Prolog unification</B></TD>
</TR></TABLE></DIV></TD>
</TR></TABLE>
<BR>
<B>Templates</B>
<DL COMPACT=compact><DT><DD><TT>
=(?term, ?term)</TT></DL>
<B>Description</B><BR>
<BR>
<TT>Term1 = Term2</TT> unifies <TT>Term1</TT> and <TT>Term2</TT>. No occurs
check is done, i.e. this predicate does not check if a variable is unified
with a compound term containing this variable (this can lead to an infinite
loop).<BR>
<BR>
<TT>=</TT> is a predefined infix operator (section <A HREF="manual037.html#op/3:(Term-input/output)">7.14.10</A>).<BR>
<BR>
<B>Errors</B><BR>
<BR>
None.<BR>
<BR>
<B>Portability</B><BR>
<BR>
ISO predicate.<BR>
<BR>
<A NAME="toc46"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%">
<TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE>
<TR><TD><B><A NAME="htoc70">7.2.2</A></B></TD>
<TD WIDTH="100%" ALIGN=center><TT><B>unify_with_occurs_check/2</B></TT></TD>
</TR></TABLE></DIV></TD>
</TR></TABLE>
<BR>
<B>Templates</B>
<DL COMPACT=compact><DT><DD><TT>
unify_with_occurs_check(?term, ?term)
</TT></DL>
<B>Description</B><BR>
<BR>
<TT>unify_with_occurs_check(Term1, Term2)</TT> unifies <TT>Term1</TT> and
<TT>Term2</TT>. The occurs check test is done (i.e. the unification fails if
a variable is unified with a compound term containing this variable).<BR>
<BR>
<B>Errors</B><BR>
<BR>
None.<BR>
<BR>
<B>Portability</B><BR>
<BR>
ISO predicate.<BR>
<BR>
<A NAME="toc47"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%">
<TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE>
<TR><TD><B><A NAME="htoc71">7.2.3</A></B></TD>
<TD WIDTH="100%" ALIGN=center><B><TT>(\=)/2</TT> - not Prolog unifiable</B></TD>
</TR></TABLE></DIV></TD>
</TR></TABLE>
<BR>
<B>Templates</B>
<DL COMPACT=compact><DT><DD><TT>
\=(?term, ?term)
</TT></DL>
<B>Description</B><BR>
<BR>
<TT>Term1 \= Term2</TT> succeeds if <TT>Term1</TT> and <TT>Term2</TT>
are not unifiable (no occurs check is done). <TT><BR>
<BR>
\=</TT> is a predefined infix operator (section <A HREF="manual037.html#op/3:(Term-input/output)">7.14.10</A>).<BR>
<BR>
<B>Errors</B><BR>
<BR>
None.<BR>
<BR>
<B>Portability</B><BR>
<BR>
ISO predicate.<BR>
<BR>
<HR SIZE=2>
Copyright (C) 1999-2002 Daniel Diaz
<BR>
<BR>
Verbatim copying and distribution of this entire article is permitted in any
medium, provided this notice is preserved. <BR>
<BR>
<A HREF="index.html#copyright">More about the copyright</A>
<HR>
<A HREF="manual024.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A>
<A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A>
<A HREF="manual026.html"><IMG SRC ="next_motif.gif" ALT="Next"></A>
</BODY>
</HTML>
