fixed typo

diff --git a/doc/tutorial/ginac.texi b/doc/tutorial/ginac.texi
index e3340e68a85ac6b60e9fd31cb64997d59d853b74..38b8c93a9d7b461601e2f9942c5e1607bd0f5d68 100644 (file)
--- a/doc/tutorial/ginac.texi
+++ b/doc/tutorial/ginac.texi
@@ -6469,6 +6469,7 @@ The following shows how to build a simple package using automake
 and the @samp{AM_PATH_GINAC} macro. The program used here is @file{simple.cpp}:
 
 @example
+#include <iostream>
 #include <ginac/ginac.h>
 
 int main(void)