X-Git-Url: https://pintos-os.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=doc%2Fexpressions.texi;h=d27d11b40744a467de4ddcaaf57fccbe55c0ac41;hb=0054d7bf45fb09a455698d1a180db93055f49dba;hp=5898d53d77cd0c604666de83b5d171e6c5c8be2a;hpb=63387e3d127359bab6c4f53c27a9131ab4a9c348;p=pspp

diff --git a/doc/expressions.texi b/doc/expressions.texi
index 5898d53d77..d27d11b407 100644
--- a/doc/expressions.texi
+++ b/doc/expressions.texi
@@ -342,9 +342,14 @@ FUZZBITS}), which is 6 unless overridden.
 @end deftypefn
 
 @cindex truncation
-@deftypefn {Function} {} TRUNC (@var{number})
-Discards the fractional part of @var{number}; that is, rounds
-@var{number} towards zero.
+@deftypefn {Function} {} TRUNC (@var{number} [, @var{mult}[, @var{fuzzbits}]])
+Rounds @var{number} to a multiple of @var{mult}, toward zero.  For the
+default @var{mult} of 1, this is equivalent to discarding the
+fractional part of @var{number}.  Values that fall short of a multiple
+of @var{mult} by less than @var{fuzzbits} of errors in the
+least-significant bits of @var{number} are rounded away from zero.  If
+@var{fuzzbits} is not specified then the default is taken from SET
+FUZZBITS (@pxref{SET FUZZBITS}), which is 6 unless overridden.
 @end deftypefn
 
 @node Trigonometry