--- a/doc/interpreter/arith.txi
+++ b/doc/interpreter/arith.txi
@@ -119,17 +119,21 @@
 angle in degrees.
 
 Octave uses the C library trigonometric functions.  It is expected that these
-functions are defined by the ISO/IEC 9899 standard. This Standard is available
-at: http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf.  Section F.9.1 deals
-with the trigonometric functions.  The behavior of most of the functions is
-relatively straightforward. However, there are some exceptions to the standard
-behavior.  Many of the exceptions involve the behavior for -0.
-The most complex case is atan2. Octave exactly implements the behavior given
-in the Standard.  Including @tex $atan2(\pm0, -0)$ @end tex @ifnottex @code 
-{atan2(+- 0, 0)} @end ifnottex
-returns @tex $\pm \pi.$@end tex @ifnottex @code{+- pi}.
+functions are defined by the ISO/IEC 9899 Standard.  This Standard is available
+at: @url{http://www.open-std.org/jtc1/sc22/wg14/www/docs/n1124.pdf}.
+Section F.9.1 deals with the trigonometric functions.  The behavior of most of
+the functions is relatively straightforward.  However, there are some
+exceptions to the standard behavior.  Many of the exceptions involve the
+behavior for -0.  The most complex case is atan2.  Octave exactly implements
+the behavior given in the Standard.  Including
+@tex
+$atan2(\pm0, -0)$ returns $\pm \pi$.
+@end tex
+@ifnottex
+@code{atan2(+- 0, 0)} returns @code{+- pi}.
+@end ifnottex
 
-It should be noted that Matlab uses different definitions which apparently
+It should be noted that @sc{matlab} uses different definitions which apparently
 do not distinguish -0.
 
 @DOCSTRING(sin)