Correct argument specifications of load_compiled and load_source: the file
argument is optional on both (the format string is "ss|O!").
diff --git a/Doc/lib/libimp.tex b/Doc/lib/libimp.tex
index 31368f4..ffab5c9 100644
--- a/Doc/lib/libimp.tex
+++ b/Doc/lib/libimp.tex
@@ -192,7 +192,7 @@
 no such module.
 \end{funcdesc}
 
-\begin{funcdesc}{load_compiled}{name, pathname, file}
+\begin{funcdesc}{load_compiled}{name, pathname, \optional{file}}
 \indexii{file}{byte-code}
 Load and initialize a module implemented as a byte-compiled code file
 and return its module object.  If the module was already initialized,
@@ -218,7 +218,7 @@
 support it.)
 \end{funcdesc}
 
-\begin{funcdesc}{load_source}{name, pathname, file}
+\begin{funcdesc}{load_source}{name, pathname\optional{, file}}
 Load and initialize a module implemented as a Python source file and
 return its module object.  If the module was already initialized, it
 will be initialized \emph{again}.  The \var{name} argument is used to