Added built-in predicate format/1 for compatibility with SWI-Prolog.

git-svn-id: https://yap.svn.sf.net/svnroot/yap/trunk@2303 b08c6af1-5177-4d33-ba66-4b1c6b8b522a

docs/yap.tex

@@ -4854,6 +4854,14 @@ The two @code{~t} escape sequence force filling both before and after
 @code{Hello}. Space is then evenly divided between the right and the
 left sides.
 
+
+@item format(+@var{T})
+@findex format/1
+@saindex format/1
+@cnindex format/1
+Print formatted output to the current output stream.
+
+
 @item format(+@var{S},+@var{T},+@var{L})
 @findex format/3
 @saindex format/3

pl/yio.yap

@@ -592,6 +592,10 @@ print(Stream,T) :-
 print(_,_).
 
 
+format(T) :-
+	format(T, []).
+
+
 /* interface to user portray	*/
 '$portray'(T) :-
 	\+ '$undefined'(portray(_),user),