Reworded fabs() for consistency with the others. Noted that all

return values are floats.

Doc/lib/libmath.tex

@@ -17,7 +17,8 @@ complex result allows earlier detection of the unexpected complex
 number used as a parameter, so that the programmer can determine how
 and why it was generated in the first place.
 
-The following functions are provided by this module:
+The following functions are provided by this module.  Except
+when explicitly noted otherwise, all return values are floats:
 
 \begin{funcdesc}{acos}{x}
 Return the arc cosine of \var{x}.
@@ -56,7 +57,7 @@ Return \code{e**\var{x}}.
 \end{funcdesc}
 
 \begin{funcdesc}{fabs}{x}
-Return the absolute value of the floating point number \var{x}.
+Return the absolute value of \var{x}.
 \end{funcdesc}
 
 \begin{funcdesc}{floor}{x}