<!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 input/output </TITLE> </HEAD> <BODY TEXT=black BGCOLOR=white> <A HREF="manual036.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual038.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="htoc150">7.14</A></B></FONT></TD> <TD WIDTH="100%" ALIGN=center><FONT SIZE=4><B>Term input/output</B></FONT></TD> </TR></TABLE></DIV></TD> </TR></TABLE><UL> <LI><A HREF="manual037.html#toc115"> <TT>read_term/3</TT>, <TT>read_term/2</TT>, <TT>read/2</TT>, <TT>read/1</TT></A> <LI><A HREF="manual037.html#toc116"> <TT>read_atom/2</TT>, <TT>read_atom/1</TT>, <TT>read_integer/2</TT>, <TT>read_integer/1</TT>,<BR> <TT>read_number/2</TT>, <TT>read_number/1</TT></A> <LI><A HREF="manual037.html#toc117"> <TT>read_token/2</TT>, <TT>read_token/1</TT></A> <LI><A HREF="manual037.html#toc118"> <TT>syntax_error_info/4</TT></A> <LI><A HREF="manual037.html#toc119"> <TT>last_read_start_line_column/2</TT></A> <LI><A HREF="manual037.html#toc120"> <TT>write_term/3</TT>, <TT>write_term/2</TT>, <TT>write/2</TT>, <TT>write/1</TT>, <TT>writeq/2</TT>, <TT>writeq/1</TT>,<BR> <TT>write_canonical/2</TT>, <TT>write_canonical/1</TT>, <TT>display/2</TT>, <TT>display/1</TT>, <TT>print/2</TT>,<BR> <TT>print/1</TT></A> <LI><A HREF="manual037.html#toc121"> <TT>format/3</TT>, <TT>format/2</TT></A> <LI><A HREF="manual037.html#toc122"> <TT>portray_clause/2</TT>, <TT>portray_clause/1</TT></A> <LI><A HREF="manual037.html#toc123"> <TT>get_print_stream/1</TT></A> <LI><A HREF="manual037.html#toc124"> <TT>op/3</TT></A> <LI><A HREF="manual037.html#toc125"> <TT>current_op/3</TT></A> <LI><A HREF="manual037.html#toc126"> <TT>char_conversion/2</TT></A> <LI><A HREF="manual037.html#toc127"> <TT>current_char_conversion/2</TT></A> </UL> <A NAME="Term-input/output"></A> These built-in predicates enable a Prolog term to be input from or output to a text stream. The atom <TT>end_of_file</TT> is returned as term to indicate the end-of-file. The syntax of such terms can also be altered by changing the operators (section <A HREF="#op/3:(Term-input/output)">7.14.10</A>), and making some characters equivalent to others (section <A HREF="#char-conversion/2">7.14.12</A>) if the <TT>char_conversion</TT> Prolog flag is <TT>on</TT> (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>). Double quoted tokens will be returned as an atom or a character list or a character code list depending on the value of the <TT>double_quotes</TT> Prolog flag (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>). Similarly, back quoted tokens are returned depending on the value of the <TT>back_quotes</TT> Prolog flag.<BR> <BR> <A NAME="toc115"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc151">7.14.1</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>read_term/3</TT>, <TT>read_term/2</TT>, <TT>read/2</TT>, <TT>read/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="read-term/3"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> read_term(+stream_or_alias, ?term, +read_option_list)<BR> read_term(?term, +read_option_list)<BR> read(+stream_or_alias, ?term)<BR> read(?term)</TT></DL> <B>Description</B><BR> <BR> <TT>read_term(SorA, Term, Options)</TT> is true if <TT>Term</TT> unifies with the next term read from the stream associated with the stream-term or alias <TT>SorA</TT> according to the options given by <TT>Options</TT>.<BR> <BR> <B>Read options</B>: <TT>Options</TT> is a list of read options. If this list contains contradictory options, the rightmost option is the one which applies. Possible options are: <UL><LI><TT>variables(VL)</TT>: <TT>VL</TT> is unified with the list of all variables of the input term, in left-to-right traversal order. Anonymous variables are included in the list <TT>VL</TT>.<BR> <BR> <LI><TT>variable_names(VNL)</TT>: <TT>VNL</TT> is unified with the list of pairs <TT>Name = Var</TT> where <TT>Var</TT> is a named variable of the term and <TT>Name</TT> is the atom associated to the name of <TT>Var</TT>. Anonymous variables are not included in the list <TT>VNL</TT>.<BR> <BR> <LI><TT>singletons(SL)</TT>: <TT>SL</TT> is unified with the list of pairs <TT>Name = Var</TT> where <TT>Var</TT> is a named variable which occurs only once in the term and <TT>Name</TT> is the atom associated to the name of <TT>Var</TT>. Anonymous variables are not included in the list <TT>SL</TT>.<BR> <BR> <LI><TT>syntax_error(error</TT>/<TT>warning</TT>/<TT>fail)</TT>: specifies the effect of a syntax error: <UL><LI><TT>error</TT>: a <TT>syntax_error</TT> is raised.<BR> <BR> <LI><TT>warning</TT>: a warning message is displayed and the predicate fails.<BR> <BR> <LI><TT>fail</TT>: the predicate quietly fails.</UL><BR> The default value is the value of the <TT>syntax_error</TT> Prolog flag (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>).<BR> <BR> <LI><TT>end_of_term(dot</TT>/<TT>eof)</TT>: specifies the end-of-term delimiter: <TT>dot</TT> is the classical full-stop delimiter (a dot followed with a layout character), <TT>eof</TT> is the end-of-file delimiter. This option is useful for predicates like <TT>read_term_from_atom/3</TT> (section <A HREF="manual038.html#read-term-from-atom/3">7.15.1</A>) to avoid to add a terminal dot at the end of the atom. The default value is <TT>dot</TT>.</UL> <TT>read(SorA, Term)</TT> is equivalent to <TT>read_term(SorA, Term, [])</TT>.<BR> <BR> <TT>read_term/2</TT> and <TT>read/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Options</TT> is a partial list or a list with an element <TT>E</TT> which is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Options</TT> is neither a partial list nor a list</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(list, Options)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Options</TT> list is neither a variable nor a valid read option</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(read_option, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>a syntax error occurs and the value of the <TT>syntax_error</TT> Prolog flag is <TT>error</TT> (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>)</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>syntax_error(<I>atom explaining the error</I>)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicates. The ISO reference raises a <TT>representation_error(Flag)</TT> where <TT>Flag</TT> is <TT>max_arity</TT>,<TT> max_integer</TT>, or<TT> min_integer</TT> when the read term breaches an implementation defined limit specified by <TT>Flag</TT>. GNU Prolog detects neither <TT>min_integer</TT> nor <TT>max_integer</TT> violation and treats a <TT>max_arity</TT> violation as a syntax error. The read options <TT>syntax_error/1</TT> and <TT>end_of_term/1</TT> are GNU Prolog extensions.<BR> <BR> <A NAME="toc116"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc152">7.14.2</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>read_atom/2</TT>, <TT>read_atom/1</TT>, <TT>read_integer/2</TT>, <TT>read_integer/1</TT>,<BR> <TT>read_number/2</TT>, <TT>read_number/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="read-atom/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> read_atom(+stream_or_alias, ?atom)<BR> read_atom(?atom)<BR> read_integer(+stream_or_alias, ?integer)<BR> read_integer(?integer)<BR> read_number(+stream_or_alias, ?number)<BR> read_number(?number)</TT></DL> <B>Description</B><BR> <BR> <TT>read_atom(SorA, Atom)</TT> succeeds if <TT>Atom</TT> unifies with the next atom read from the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <TT>read_integer(SorA, Integer)</TT> succeeds if <TT>Integer</TT> unifies with the next integer read from the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <TT>read_number(SorA, Number)</TT> succeeds if <TT>Number</TT> unifies with the next number (integer or floating point number) read from the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <TT>read_atom/1</TT>, <TT>read_integer/1</TT> and <TT>read_number/1</TT> apply to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Atom</TT> is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, Atom)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Integer</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Integer)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Number</TT> is neither a variable nor a number</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(number, Number)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>a syntax error occurs and the value of the <TT>syntax_error</TT> Prolog flag is <TT>error</TT> (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>)</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>syntax_error(<I>atom explaining the error</I>)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates.<BR> <BR> <A NAME="toc117"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc153">7.14.3</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>read_token/2</TT>, <TT>read_token/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="read-token/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> read_token(+stream_or_alias, ?nonvar)<BR> read_token(?nonvar)</TT></DL> <B>Description</B><BR> <BR> <TT>read_token(SorA, Token)</TT> succeeds if <TT>Token</TT> unifies with the encoding of the next Prolog token read from the stream associated with stream-term or alias <TT>SorA</TT>.<BR> <BR> <B>Token encoding</B>: <UL><LI><TT>var(A)</TT>: a variable is read whose name is the atom <TT>A</TT>.<BR> <BR> <LI>an atom <TT>A</TT>: an atom <TT>A</TT> is read.<BR> <BR> <LI>integer <TT>N</TT>: an integer <TT>N</TT> is read.<BR> <BR> <LI>floating point number <TT>N</TT>: a floating point number <TT>N</TT> is read.<BR> <BR> <LI><TT>string(A)</TT>: a string (double quoted item) is read whose characters forms the atom <TT>A</TT>. <BR> <BR> <LI><TT>punct(P)</TT>: a punctuation character <TT>P</TT> is read (<TT>P</TT> is a one-character atom in <TT>()[]{|}</TT>, the atom <TT>full_stop</TT> or the atom <TT>end_of_file</TT>).<BR> <BR> <LI><TT>back_quotes(A)</TT>: a back quoted item is read whose characters forms the atom <TT>A</TT>.<BR> <BR> <LI><TT>extended(A)</TT>: an extended character <TT>A</TT> (an atom) is read.</UL> As for <TT>read_term/3</TT>, the behavior of <TT>read_token/2</TT> can be affected by some Prolog flags (section <A HREF="#Term-input/output">7.14</A>).<BR> <BR> <TT>read_token/1</TT> applies to the current input stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an output stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> has stream properties <TT>end_of_stream(past)</TT> and <TT>eof_action(error)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(input, past_end_of_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>a syntax error occurs and the value of the <TT>syntax_error</TT> Prolog flag is <TT>error</TT> (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>)</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>syntax_error(<I>atom explaining the error</I>)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates.<BR> <BR> <A NAME="toc118"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc154">7.14.4</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>syntax_error_info/4</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="syntax-error-info/4"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> syntax_error_info(?atom, ?integer, ?integer, ?atom)</TT></DL> <B>Description</B><BR> <BR> <TT>syntax_error_info(FileName, Line, Column, Error)</TT> returns the information associated to the last syntax error. <TT>Line</TT> is the line number of the error, <TT>Column</TT> is the column number of the error and <TT>Error</TT> is an atom explaining the error.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>FileName</TT> is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, FileName)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Line</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Line)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Column</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Column)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Error</TT> is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, Error)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicate.<BR> <BR> <A NAME="toc119"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc155">7.14.5</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>last_read_start_line_column/2</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> last_read_start_line_column(?integer, ?integer)</TT></DL> <B>Description</B><BR> <BR> <TT>last_read_start_line_column(Line, Column)</TT> unifies <TT>Line</TT> and <TT>Column</TT> with the line number and the column number associated to the start of the last read predicate. This predicate can be used after calling one of the following predicates: <TT>read_term/3</TT>, <TT>read_term/2</TT>, <TT>read/2</TT>, <TT>read/1</TT> (section <A HREF="#read-term/3">7.14.1</A>), <TT>read_atom/2</TT>, <TT>read_atom/1</TT>, <TT>read_integer/2</TT>, <TT>read_integer/1</TT>, <TT>read_number/2</TT>, <TT>read_number/1</TT> (section <A HREF="#read-atom/2">7.14.2</A>) or <TT>read_token/2</TT>, <TT>read_token/1</TT> (section <A HREF="#read-token/2">7.14.3</A>).<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Line</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Line)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Column</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Column)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicate.<BR> <BR> <A NAME="toc120"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc156">7.14.6</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>write_term/3</TT>, <TT>write_term/2</TT>, <TT>write/2</TT>, <TT>write/1</TT>, <TT>writeq/2</TT>, <TT>writeq/1</TT>,<BR> <TT>write_canonical/2</TT>, <TT>write_canonical/1</TT>, <TT>display/2</TT>, <TT>display/1</TT>, <TT>print/2</TT>,<BR> <TT>print/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="write-term/3"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> write_term(+stream_or_alias, ?term, +write_option_list)<BR> write_term(?term, +write_option_list)<BR> write(+stream_or_alias, ?term)<BR> write(?term)<BR> writeq(+stream_or_alias, ?term)<BR> writeq(?term)<BR> write_canonical(+stream_or_alias, ?term)<BR> write_canonical(?term)<BR> display(+stream_or_alias, ?term)<BR> display(?term)<BR> print(+stream_or_alias, ?term)<BR> print(?term)</TT></DL> <B>Description</B><BR> <BR> <TT>write_term(SorA, Term, Options)</TT> writes <TT>Term</TT> to the stream associated with the stream-term or alias <TT>SorA</TT> according to the options given by <TT>Options</TT>.<BR> <BR> <B>Write options</B>: <TT>Options</TT> is a list of write options. If this list contains contradictory options, the rightmost option is the one which applies. Possible options are: <UL><LI><TT>quoted(true</TT>/<TT>false)</TT>: if <TT>true</TT> each atom and functor is quoted if this would be necessary for the term to be input by <TT>read_term/3</TT>. If <TT>false</TT> no extra quotes are written. The default value is <TT>false</TT>.<BR> <BR> <LI><TT>ignore_ops(true</TT>/<TT>false)</TT>: if <TT>true</TT> each compound term is output in functional notation (neither operator notation nor list notation is used). If <TT>false</TT> operator and list notations are used. The default value is <TT>false</TT>.<BR> <BR> <LI><TT>numbervars(true</TT>/<TT>false)</TT>: if <TT>true</TT> a term of the form <TT>'$VAR'(N)</TT>, where <TT>N</TT> is an integer, is output as a variable name (see below). If <TT>false</TT> such a term is output normally (according to the other options). The default value is <TT>true</TT>.<BR> <BR> <LI><TT>namevars(true</TT>/<TT>false)</TT>: if <TT>true</TT> a term of the form <TT>'$VARNAME'(Name)</TT>, where <TT>Name</TT> is an atom, is output as a variable name (see below). If <TT>false</TT> such a term is output normally (according to the other options). The default value is <TT>true</TT>.<BR> <BR> <LI><TT>space_args(true</TT>/<TT>false)</TT>: if <TT>true</TT> an extra space character is emitted after each comma separating the arguments of a compound term in functional notation or of a list. If <TT>false</TT> no extra space is emitted. The default value is <TT>false</TT>.<BR> <BR> <LI><TT>portrayed(true</TT>/<TT>false)</TT>: if <TT>true</TT> and if there exists a predicate <TT>portray/1</TT>, <TT>write_term/3</TT> acts as follows: if <TT>Term</TT> is a variable it is simply written. If <TT>Term</TT> is non-variable then it is passed to <TT>portray/1</TT>. If this succeeds then it is assumed that <TT>Term</TT> has been output. Otherwise <TT>write_term/3</TT> outputs the principal functor of <TT>Term</TT> (<TT>Term</TT> itself if it is atomic) according to other options and recursively calls <TT>portray/1</TT> on the components of <TT>Term</TT> (if it is a compound term). With <TT>ignore_ops(false)</TT> a list is first passed to <TT>portray/1</TT> and only if this call fails each element of the list is passed to <TT>portray/1</TT> (thus every sub-list is not passed). The default value is <TT>false</TT>.<BR> <BR> <LI><TT>max_depth(N)</TT>: controls the depth of output for compound terms. <TT>N</TT> is an integer specifying the depth. The output of a term whose depth is greater than <TT>N</TT> gives rise to the output of <TT>...</TT> (3 dots). By default there is no depth limit.<BR> <BR> <LI><TT>priority(N)</TT>: specifies the starting priority to output the term. This option controls if <TT>Term</TT> should be enclosed in brackets. <TT>N</TT> is a positive integer <= 1200. By default <TT>N</TT> = 1200.</UL> <B>Variable numbering</B>: when the <TT>numbervars(true)</TT> option is passed to <TT>write_term/3</TT> any term of the form <TT>'$VAR'(N)</TT> where <TT>N</TT> is an integer is output as a variable name consisting of a capital letter possibly followed by an integer. The capital letter is the <TT>(I+1)</TT><EM>th</EM> letter of the alphabet and the integer is <TT>J</TT>, where <TT>I = N mod 26</TT> and <TT>J = N // 26</TT>. The integer <TT>J</TT> is omitted if it is zero. For example: <DL COMPACT=compact><DT><DD><TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD ALIGN=left NOWRAP><TT>'$VAR'(0)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD ALIGN=left NOWRAP>is written as <TT>A</TT></TD> </TR> <TR><TD ALIGN=left NOWRAP><TT>'$VAR'(1)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD ALIGN=left NOWRAP>is written as <TT>B</TT></TD> </TR> <TR><TD ALIGN=left NOWRAP COLSPAN=3><TT>...</TT></TD> </TR> <TR><TD ALIGN=left NOWRAP><TT>'$VAR'(25)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD ALIGN=left NOWRAP>is written as <TT>Z</TT></TD> </TR> <TR><TD ALIGN=left NOWRAP><TT>'$VAR'(26)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD ALIGN=left NOWRAP>is written as <TT>A1</TT></TD> </TR> <TR><TD ALIGN=left NOWRAP><TT>'$VAR'(27)</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD ALIGN=left NOWRAP>is written as <TT>B1</TT></TD> </TR></TABLE></DL> <B>Variable naming</B>: when the <TT>namevars(true)</TT> option is passed to <TT>write_term/3</TT> any term of the form <TT>'$VARNAME'(Name)</TT> where <TT>Name</TT> is an atom is output as a variable name consisting of the characters <TT>Name</TT>. For example: <TT>'$VARNAME'('A')</TT> is written as <TT>A</TT> (even in the presence of the <TT>quoted(true)</TT> option).<BR> <BR> <TT>write(SorA, Term)</TT> is equivalent to <TT>write_term(SorA, Term, [])</TT>.<BR> <BR> <TT>writeq(SorA, Term)</TT> is equivalent to <TT>write_term(SorA, Term, [quoted(true)])</TT>.<BR> <BR> <TT>write_canonical(SorA, Term)</TT> is equivalent to <TT>write_term(SorA, Term, [quoted(true),<BR> ignore_ops(true), numbervars(false)])</TT>.<BR> <BR> <TT>display(SorA, Term)</TT> is equivalent to <TT>write_term(SorA, Term, [ignore_ops(true),<BR> numbervars(false)])</TT>.<BR> <BR> <TT>print(SorA, Term)</TT> is equivalent to <TT>write_term(SorA, Term, [numbervars(false),<BR> portrayed(true)])</TT>.<BR> <BR> <TT>write_term/2</TT>, <TT>write/1</TT>, <TT>writeq/1</TT>, <TT>write_canonical/1</TT>, <TT>display/1</TT> and <TT>print/1</TT> apply to the current output stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Options</TT> is a partial list or a list with an element <TT>E</TT> which is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Options</TT> is neither a partial list nor a list</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(list, Options)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Options</TT> list is neither a variable nor a valid write-option</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(write_option, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an input stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicates except <TT>display/1-2</TT> and <TT>print/1-2</TT> that are GNU Prolog predicates. <TT>namevars/1</TT>, <TT>space_args/1</TT>, <TT>portrayed/1</TT>, <TT>max_depth/1</TT> and <TT>priority/1</TT> options are GNU Prolog extensions.<BR> <BR> <A NAME="toc121"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc157">7.14.7</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>format/3</TT>, <TT>format/2</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="format/3"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> format(+stream_or_alias, +character_code_list_or_atom, +list)<BR> format(+character_code_list_or_atom, +list)</TT></DL> <B>Description</B><BR> <BR> <TT>format(SorA, Format, Arguments)</TT> writes the <TT>Format</TT> string replacing each format control sequence <TT>F</TT> by the corresponding element of <TT>Arguments</TT> (formatted according to <TT>F</TT>) to the stream associated with the stream-term or alias <TT>SorA</TT>.<BR> <BR> <B>Format control sequences</B>: the general format of a control sequence is <TT>'~NC'</TT>. The character <TT>C</TT> determines the type of the control sequence. <TT>N</TT> is an optional numeric argument. An alternative form of <TT>N</TT> is <TT>'*'</TT>. <TT>'*'</TT> implies that the next argument <TT>Arg</TT> in <TT>Arguments</TT> should be used as a numeric argument in the control sequence. The use of C <TT>printf()</TT> formatting sequence (beginning by the character <TT>%</TT>) is also allowed. The following control sequences are available:<BR> <TABLE BORDER=1 CELLSPACING=0 CELLPADDING=1> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center>Format sequence</DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>type of the argument</DIV></TD> <TD VALIGN=top ALIGN=left>Description</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Na</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>atom</DIV></TD> <TD VALIGN=top ALIGN=left>print the atom without quoting. <TT>N</TT> is minimal number of characters to print using spaces on the rigth if needed (default: the length of the atom)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Nc</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>character code</DIV></TD> <TD VALIGN=top ALIGN=left>print the character associated to the code. <TT>N</TT> is the number of times to print the character (default: 1)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT> ~Nf</TT> <BR> <TT>~Ne ~NE ~Ng ~NG</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>float expression</DIV></TD> <TD VALIGN=top ALIGN=left>pass the argument <TT>Arg</TT> and <TT>N</TT> to the C <TT>printf()</TT> function as: <BR> if <TT>N</TT> is not specified <TT>printf("%f",Arg)</TT> else <TT>printf("%.Nf",Arg)</TT>. <BR> Similarly for <TT>~Ne</TT>, <TT>~NE</TT>, <TT>~Ng</TT> and <TT>~NG</TT></TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Nd</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>integer expression</DIV></TD> <TD VALIGN=top ALIGN=left>print the argument. <TT>N</TT> is the number of digits after the decimal point. If <TT>N</TT> is 0 no decimal point is printed (default: 0)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~ND</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>integer expression</DIV></TD> <TD VALIGN=top ALIGN=left>identical to <TT>~Nd</TT> except that <TT>','</TT> separates groups of three digits to the left of the decimal point</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Nr</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>integer expression</DIV></TD> <TD VALIGN=top ALIGN=left>print the argument according to the radix <TT>N</TT>. 2 <= <TT>N</TT> <= 36 (default: 8). The letters <TT>a-z</TT> denote digits > 9</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~NR</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>integer expression</DIV></TD> <TD VALIGN=top ALIGN=left>identical to <TT>~Nr</TT> except that the letters <TT>A-Z</TT> denote digits > 9</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Ns</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>character code list</DIV></TD> <TD VALIGN=top ALIGN=left>print exactly <TT>N</TT> characters (default: the length of the list)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~NS</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>character list</DIV></TD> <TD VALIGN=top ALIGN=left>print exactly <TT>N</TT> characters (default: the length of the list)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~i</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>term</DIV></TD> <TD VALIGN=top ALIGN=left>ignore the current argument</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~k</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>term</DIV></TD> <TD VALIGN=top ALIGN=left>pass the argument to <TT>write_canonical/1</TT> (section <A HREF="#write-term/3">7.14.6</A>)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~p</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>term</DIV></TD> <TD VALIGN=top ALIGN=left>pass the argument to <TT>print/1</TT> (section <A HREF="#write-term/3">7.14.6</A>)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~q</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>term</DIV></TD> <TD VALIGN=top ALIGN=left>pass the argument to <TT>writeq/1</TT> (section <A HREF="#write-term/3">7.14.6</A>)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~w</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>term</DIV></TD> <TD VALIGN=top ALIGN=left>pass the argument to <TT>write/1</TT> (section <A HREF="#write-term/3">7.14.6</A>)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~~</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>none</DIV></TD> <TD VALIGN=top ALIGN=left>print the character <TT>'~'</TT></TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~Nn</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>none</DIV></TD> <TD VALIGN=top ALIGN=left>print <TT>N</TT> new-line characters (default: 1)</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~N</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>none</DIV></TD> <TD VALIGN=top ALIGN=left>print a new-line character if not at the beginning of a line</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>~?</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>atom</DIV></TD> <TD VALIGN=top ALIGN=left>use the argument as a nested format string</TD> </TR> <TR><TD VALIGN=top ALIGN=left><DIV ALIGN=center><TT>%F</TT></DIV></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=center>atom, integer or float expression</DIV></TD> <TD VALIGN=top ALIGN=left>interface to the C function <TT>printf(3)</TT> for outputting atoms (C string), integers and floating point numbers. <TT>*</TT> are also allowed.</TD> </TR></TABLE><BR> <TT>format/2</TT> applies to the current output stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Format</TT> is a partial list or a list with an element <TT>E</TT> which is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Arguments</TT> is a partial list</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Format</TT> is neither a partial list nor a list or an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(list, Format)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Arguments</TT> is neither a partial list nor a list</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(list, Arguments)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Format</TT> list is neither a variable nor a character code</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character_code, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of Format is not a valid format control sequence</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(format_control_sequence, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>the <TT>Arguments</TT> list does not contain sufficient elements</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(non_empty_list, [])</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Arguments</TT> list is a variable while a non-variable term was expected</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Arguments</TT> list is neither variable nor an atom while an atom was expected</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Arguments</TT> cannot be evaluated as an arithmetic expression while an integer or a floating point number was expected</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left>an arithmetic error (section <A HREF="manual029.html#Evaluation-of-an-arithmetic-expression">7.6.1</A>)</TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Arguments</TT> list is neither variable nor character code while a character code was expected</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>representation_error(character_code, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an input stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates. <BR> <BR> <A NAME="toc122"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc158">7.14.8</A></B></TD> <TD WIDTH="100%" ALIGN=center><B><TT>portray_clause/2</TT>, <TT>portray_clause/1</TT></B></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="portray-clause/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> portray_clause(+stream_or_alias, +clause)<BR> portray_clause(+clause)</TT></DL> <B>Description</B><BR> <BR> <TT>portray_clause(SorA, Clause)</TT> pretty prints <TT>Clause</TT> to the stream associated with the stream-term or alias <TT>SorA</TT>. <TT>portray_clause/2</TT> uses the variable binding predicates <TT>name_singleton_vars/1</TT> (section <A HREF="manual028.html#name-singleton-vars/1">7.5.1</A>) and <TT>numbervars/1</TT> (section <A HREF="manual028.html#bind-variables/2">7.5.3</A>). This predicate is used by <TT>listing/1</TT> (section <A HREF="manual046.html#listing/1">7.23.3</A>).<BR> <BR> <TT>portray_clause/1</TT> applies to the current output stream.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Clause</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Clause</TT> is neither a variable nor a callable term</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(callable, Clause)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is neither a variable nor a stream-term or alias</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream_or_alias, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is not associated with an open stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>existence_error(stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is an input stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>SorA</TT> is associated with a binary stream</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(output, binary_stream, SorA)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicates.<BR> <BR> <A NAME="toc123"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc159">7.14.9</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>get_print_stream/1</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> get_print_stream(?stream)</TT></DL> <B>Description</B><BR> <BR> <TT>get_print_stream(Stream)</TT> unifies <TT>Stream</TT> with the stream-term associated to the output stream used by <TT>print/2</TT> (section <A HREF="#write-term/3">7.14.6</A>). The purpose of this predicate is to allow a user-defined <TT>portray/1</TT> predicate to identify the output stream in use.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Stream</TT> is neither a variable nor a stream-term</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(stream, Stream)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> GNU Prolog predicate.<BR> <BR> <A NAME="toc124"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc160">7.14.10</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>op/3</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="op/3:(Term-input/output)"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> op(+integer, +operator_specifier, +atom_or_atom_list)</TT></DL> <B>Description</B><BR> <BR> <TT>op(Priority, OpSpecifier, Operator)</TT> alters the operator table. <TT>Operator</TT> is declared as an operator with properties defined by specifier <TT>OpSpecifier</TT> and <TT>Priority</TT>. <TT>Priority</TT> must be an integer >= 0 and <= 1200. If <TT>Priority</TT> is 0 then the operator properties of <TT>Operator</TT> (if any) are canceled. <TT>Operator</TT> may also be a list of atoms in which case all of them are declared to be operators. In general, operators can be removed from the operator table and their priority or specifier can be changed. However, it is an error to attempt to change the <TT>','</TT> operator from its initial status. An atom can have multiple operator definitions (e.g. prefix and infix like <TT>+</TT>) however an atom cannot have both an infix and a postfix operator definitions.<BR> <BR> <B>Operator specifiers</B>: the following specifiers are available:<BR> <TABLE BORDER=1 CELLSPACING=0 CELLPADDING=1> <TR><TD ALIGN=center NOWRAP>Specifier</TD> <TD ALIGN=center NOWRAP>Type</TD> <TD ALIGN=center NOWRAP>Associativity</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>fx</TT></TD> <TD ALIGN=center NOWRAP>prefix</TD> <TD ALIGN=center NOWRAP>no</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>fy</TT></TD> <TD ALIGN=center NOWRAP>prefix</TD> <TD ALIGN=center NOWRAP>yes</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>xf</TT></TD> <TD ALIGN=center NOWRAP>postfix</TD> <TD ALIGN=center NOWRAP>no</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>yf</TT></TD> <TD ALIGN=center NOWRAP>postfix</TD> <TD ALIGN=center NOWRAP>yes</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>xfx</TT></TD> <TD ALIGN=center NOWRAP>infix</TD> <TD ALIGN=center NOWRAP>no</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD ALIGN=center NOWRAP>infix</TD> <TD ALIGN=center NOWRAP>left</TD> </TR> <TR><TD ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD ALIGN=center NOWRAP>infix</TD> <TD ALIGN=center NOWRAP>right</TD> </TR></TABLE><BR> <B>Prolog predefined operators</B>:<BR> <TABLE BORDER=1 CELLSPACING=0 CELLPADDING=1> <TR><TD VALIGN=top ALIGN=right NOWRAP>Priority</TD> <TD VALIGN=top ALIGN=center NOWRAP>Specifier</TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left>Operators</DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>1200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>:- --></TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>1200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>fx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>:-</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>1100</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>;</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>1050</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>-></TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>1000</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>,</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>900</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>fy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>\+</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>700</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>= \= =.. == \== @< @=< @> @>= is =:= =\= < =< > >=</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>600</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>:</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>500</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>+ - /\ \/</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>400</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>* / // rem mod << >></TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>** ^</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>fy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>+ - \</TT></DIV></TD> </TR></TABLE><BR> <B>FD predefined operators</B>:<BR> <TABLE BORDER=1 CELLSPACING=0 CELLPADDING=1> <TR><TD VALIGN=top ALIGN=right NOWRAP>Priority</TD> <TD VALIGN=top ALIGN=center NOWRAP>Specifier</TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left>Operators</DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>750</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>#<=> #\<=></TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>740</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>#==> #\==></TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>730</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>## #\/ #\\/</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>720</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>#/\ #\/\</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>710</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>fy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>#\</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>700</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>#= #\= #< #=< #> #>= #=# #\=# #<# #=<# #># #>=#</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>500</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>+ -</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>400</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>yfx</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>* / // rem</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>xfy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>**</TT></DIV></TD> </TR> <TR><TD VALIGN=top ALIGN=right NOWRAP><TT>200</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP><TT>fy</TT></TD> <TD VALIGN=top ALIGN=left><DIV ALIGN=left><TT>+ -</TT></DIV></TD> </TR></TABLE><BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Priority</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OpSpecifier</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Operator</TT> is a partial list or a list with an element <TT>E</TT> which is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Priority</TT> is neither a variable nor an integer</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(integer, Priority)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OpSpecifier</TT> is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, OpSpecifier)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Operator</TT> is neither a partial list nor a list nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(list, Operator)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left>an element <TT>E</TT> of the <TT>Operator</TT> list is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, E)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Priority</TT> is an integer not >= 0 and <= 1200</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(operator_priority, Priority)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OpSpecifier</TT> is not a valid operator specifier</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(operator_specifier, OpSpecifier)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Operator</TT> is <TT>','</TT> or an element of the <TT>Operator</TT> list is <TT>','</TT></TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(modify, operator, ',')</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OpSpecifier</TT> is a specifier such that <TT>Operator</TT> would have a postfix and an infix definition.</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>permission_error(create, operator, Operator)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicate. <BR> <BR> The ISO reference implies that if a program calls <TT>current_op/3</TT>, then modifies an operator definition by calling <TT>op/3</TT> and backtracks into the call to <TT>current_op/3</TT>, then the changes are guaranteed not to affect that <TT>current_op/3</TT> goal. This is not guaranteed by GNU Prolog.<BR> <BR> <A NAME="toc125"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc161">7.14.11</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>current_op/3</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> current_op(?integer, ?operator_specifier, ?atom)</TT></DL> <B>Description</B><BR> <BR> <TT>current_op(Priority, OpSpecifier, Operator)</TT> succeeds if <TT>Operator</TT> is an operator with properties defined by specifier <TT>OpSpecifier</TT> and <TT>Priority</TT>. This predicate is re-executable on backtracking.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Priority</TT> is neither a variable nor an operator priority</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(operator_priority, Priority)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OpSpecifier</TT> is neither a variable nor an operator specifier</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>domain_error(operator_specifier, OpSpecifier)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>Operator</TT> is neither a variable nor an atom</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(atom, Operator)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicate. <BR> <BR> <A NAME="toc126"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc162">7.14.12</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>char_conversion/2</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="char-conversion/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> char_conversion(+character, +character)</TT></DL> <B>Description</B><BR> <BR> <TT>char_conversion(InChar, OutChar)</TT> alters the character-conversion mapping. This mapping is used by the following read predicates: <TT>read_term/3</TT> (section <A HREF="#read-term/3">7.14.1</A>), <TT>read_atom/2</TT>, <TT>read_integer/2</TT>, <TT>read_number/2</TT> (section <A HREF="#read-atom/2">7.14.2</A>) and <TT>read_token/2</TT> (section <A HREF="#read-token/2">7.14.3</A>) to replace any occurrence of a character <TT>InChar</TT> by <TT>OutChar</TT>. However the conversion mechanism should have been previously activated by switching on the <TT>char_conversion</TT> Prolog flag (section <A HREF="manual045.html#set-prolog-flag/2">7.22.1</A>). When <TT>InChar</TT> and <TT>OutChar</TT> are the same, the effect is to remove any conversion of a character <TT>InChar</TT>.<BR> <BR> Note that the single character read predicates (e.g. <TT>get_char/2</TT>) never do character conversion. If such behavior is required, it must be explicitly done using <TT>current_char_conversion/2</TT> (section <A HREF="#current-char-conversion/2">7.14.13</A>).<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>InChar</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OutChar</TT> is a variable</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>instantiation_error</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>InChar</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, InChar)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OutChar</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, OutChar)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicate. The <TT>type_error(character,...)</TT> is a GNU Prolog behavior, the ISO reference instead defines a <TT>representation_error(character)</TT> in this case. This seems to be an error of the ISO reference since, for many other built-in predicates accepting a character (e.g. <TT>char_code/2</TT>, <TT>put_char/2</TT>), a <TT>type_error</TT> is raised. <BR> <BR> The ISO reference implies that if a program calls <TT>current_char_conversion/2</TT>, then modifies the character mapping by calling <TT>char_conversion/2</TT>, and backtracks into the call to <TT>current_char_conversion/2</TT> then the changes are guaranteed not to affect that <TT>current_char_conversion/2</TT> goal. This is not guaranteed by GNU Prolog.<BR> <BR> <A NAME="toc127"></A><TABLE CELLPADDING=0 CELLSPACING=0 WIDTH="100%"> <TR><TD BGCOLOR="#98e7ff"><DIV ALIGN=center><TABLE> <TR><TD><B><A NAME="htoc163">7.14.13</A></B></TD> <TD WIDTH="100%" ALIGN=center><TT><B>current_char_conversion/2</B></TT></TD> </TR></TABLE></DIV></TD> </TR></TABLE> <A NAME="current-char-conversion/2"></A> <BR> <B>Templates</B> <DL COMPACT=compact><DT><DD><TT> current_char_conversion(?character, ?character)</TT></DL> <B>Description</B><BR> <BR> <TT>current_char_conversion(InChar, OutChar)</TT> succeeds if the conversion of <TT>InChar</TT> is <TT>OutChar</TT> according to the character-conversion mapping. In that case, <TT>InChar</TT> and <TT>OutChar</TT> are different. This predicate is re-executable on backtracking.<BR> <BR> <B>Errors</B><BR> <TABLE CELLSPACING=2 CELLPADDING=0> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>InChar</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, InChar)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR> <TR><TD VALIGN=top ALIGN=left><TT>OutChar</TT> is neither a variable nor a character</TD> <TD VALIGN=top ALIGN=center NOWRAP> </TD> <TD VALIGN=top ALIGN=left><TT>type_error(character, OutChar)</TT></TD> </TR> <TR><TD BGCOLOR=black COLSPAN=3><TABLE BORDER=0 WIDTH="100%" CELLSPACING=0 CELLPADDING=1><TR><TD></TD></TR></TABLE></TD> </TR></TABLE><BR> <B>Portability</B><BR> <BR> ISO predicate. Same remark as for char_conversion/2 (section <A HREF="#char-conversion/2">7.14.12</A>).<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="manual036.html"><IMG SRC ="previous_motif.gif" ALT="Previous"></A> <A HREF="manual023.html"><IMG SRC ="contents_motif.gif" ALT="Contents"></A> <A HREF="manual038.html"><IMG SRC ="next_motif.gif" ALT="Next"></A> </BODY> </HTML>