install.markdown

+in the etc directory are necessary external libraries 
+to use (especially ALVAR) there is necessary to set environment variables 
+the exports.sh does is
+just run 
+
+```bash
+. exports.sh
+```
 ALVAR library 
 --------------------
 the workflow described in ALVAR is for me is not working for me 
@@ -11,6 +19,7 @@ make
 ```
 the libraries are then in mybuild/src
 
+
 VFLIB
 ---------
 library for graph isomorphism