Description: configure default HOL Light source directory
Author: Hendrik Tews <hendrik@askra.de>
--- a/hol.ml
+++ b/hol.ml
@@ -11,10 +11,18 @@
 
 let hol_version = "2.20++";;
 
+let debian_hol_light_dir = "/usr/share/hol-light";;
+
 #directory "+compiler-libs";;
 
 let hol_dir = ref
-  (try Sys.getenv "HOLLIGHT_DIR" with Not_found -> Sys.getcwd());;
+  (try Sys.getenv "HOLLIGHT_DIR"
+   with Not_found ->
+     try
+       if Sys.is_directory debian_hol_light_dir
+       then debian_hol_light_dir
+       else raise (Sys_error "")
+     with Sys_error _ -> Sys.getcwd());;
 
 (* ------------------------------------------------------------------------- *)
 (* Should eventually change to "ref(Filename.temp_dir_name)".                *)
