diff --git a/test/alea-coloring/my-rdbg-tuning.ml b/test/alea-coloring/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/alea-coloring/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/alea-coloring/my-rdbg-tuning.ml b/test/alea-coloring/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..9ba333d82207840466e748a80995cb21eab12ec7
--- /dev/null
+++ b/test/alea-coloring/my-rdbg-tuning.ml
@@ -0,0 +1,6 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+
+
+
diff --git a/test/async-unison/Makefile b/test/async-unison/Makefile
index 52da8a2a22ce9d365f685da36e06c2e0c541c716..2765bf8cf7b198930a5f29fcd2763db9b6563fb3 100644
--- a/test/async-unison/Makefile
+++ b/test/async-unison/Makefile
@@ -1,7 +1,7 @@
-# Time-stamp: <modified the 17/10/2019 (at 17:18) by Erwan Jahier>
+# Time-stamp: <modified the 23/10/2019 (at 11:43) by Erwan Jahier>
 
 
-test: ring.cmxs ring.lut
+test: ring.cmxs ring.lut rdbg_test
 	$(sasa) -l 500 ring.dot 
 
 
@@ -16,6 +16,9 @@ lurette: ring.cmxs
       -sut "sasa -rif ring.dot -cd"  \
 		-oracle "lv6 -2c-exec ring_oracle.lus -n oracle" 
 
+rdbg_test: ring.ml
+	echo "\nnr\nsd\n" | rdbg  -o ring.rif -l 10000 -env "$(sasa) -vl 1 ring.dot -cd" 
+
 rdbg: ring.ml
 	rdbg -o ring.rif -l 10000 \
       -env "$(sasa) -vl 1 ring.dot -cd" 
diff --git a/test/async-unison/my-rdbg-tuning.ml b/test/async-unison/my-rdbg-tuning.ml
index f42644e96dabdd172a901484aeec3fd238f3f5d2..a6e1a16d550248da9b9562150dfc582d86793df1 100644
--- a/test/async-unison/my-rdbg-tuning.ml
+++ b/test/async-unison/my-rdbg-tuning.ml
@@ -2,7 +2,5 @@
 #use "../my-rdbg-tuning.ml";;
 #use "async_unison_oracle.ml";;
 
-let _ =  
- ne ();;
 
 
diff --git a/test/bfs-spanning-tree/my-rdbg-tuning.ml b/test/bfs-spanning-tree/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/bfs-spanning-tree/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/bfs-spanning-tree/my-rdbg-tuning.ml b/test/bfs-spanning-tree/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..82813d6dd7166c61c1d740335f934f70f340988a
--- /dev/null
+++ b/test/bfs-spanning-tree/my-rdbg-tuning.ml
@@ -0,0 +1,8 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+let _ =
+  dot_view:=ci;;
+
+
+
diff --git a/test/coloring/my-rdbg-tuning.ml b/test/coloring/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/coloring/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/coloring/my-rdbg-tuning.ml b/test/coloring/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..9ba333d82207840466e748a80995cb21eab12ec7
--- /dev/null
+++ b/test/coloring/my-rdbg-tuning.ml
@@ -0,0 +1,6 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+
+
+
diff --git a/test/debug_sasa/my-rdbg-tuning.ml b/test/debug_sasa/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/debug_sasa/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/debug_sasa/my-rdbg-tuning.ml b/test/debug_sasa/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..9ba333d82207840466e748a80995cb21eab12ec7
--- /dev/null
+++ b/test/debug_sasa/my-rdbg-tuning.ml
@@ -0,0 +1,6 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+
+
+
diff --git a/test/dfs-list/my-rdbg-tuning.ml b/test/dfs-list/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/dfs-list/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/dfs-list/my-rdbg-tuning.ml b/test/dfs-list/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..82813d6dd7166c61c1d740335f934f70f340988a
--- /dev/null
+++ b/test/dfs-list/my-rdbg-tuning.ml
@@ -0,0 +1,8 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+let _ =
+  dot_view:=ci;;
+
+
+
diff --git a/test/dfs/Makefile b/test/dfs/Makefile
index bb4d5363fe57c681dc127ebb4d32ace845cbec4e..bc34f0806898f1b52a4eb9e52aacb2ed8472529e 100644
--- a/test/dfs/Makefile
+++ b/test/dfs/Makefile
@@ -1,7 +1,7 @@
-# Time-stamp: <modified the 14/10/2019 (at 20:55) by Erwan Jahier>
+# Time-stamp: <modified the 23/10/2019 (at 12:21) by Erwan Jahier>
 
 
-test: test0 lurette0
+test: test0 lurette0 rdbg_test
 test0: g.cmxs g.lut
 	$(sasa) -rif -l 200 g.dot -sd 
 
@@ -26,6 +26,11 @@ rdbg: g.lut g.ml
       -env "$(sasa) g.dot  -rif" \
       -sut-nd "lutin g.lut -n dummy"
 
+rdbg_test: g.lut g.ml
+	echo "\nnr\nsd\n" | rdbg -o lurette.rif  \
+      -env "$(sasa) g.dot  -rif" \
+      -sut-nd "lutin g.lut -n dummy"
+
 
 clean: genclean
 	rm -f g_oracle.lus g.ml
diff --git a/test/dfs/my-rdbg-tuning.ml b/test/dfs/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/dfs/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/dfs/my-rdbg-tuning.ml b/test/dfs/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..151ab7a3a35c182a660e38f80deb07aa75a5b386
--- /dev/null
+++ b/test/dfs/my-rdbg-tuning.ml
@@ -0,0 +1,9 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+let _ =
+  dot_view:=ci;
+  !dot_view();;
+
+
+
diff --git a/test/dijkstra-ring/my-rdbg-tuning.ml b/test/dijkstra-ring/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/dijkstra-ring/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/dijkstra-ring/my-rdbg-tuning.ml b/test/dijkstra-ring/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..9ba333d82207840466e748a80995cb21eab12ec7
--- /dev/null
+++ b/test/dijkstra-ring/my-rdbg-tuning.ml
@@ -0,0 +1,6 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+
+
+
diff --git a/test/my-rdbg-tuning.ml b/test/my-rdbg-tuning.ml
index 5d7923d550fe13a55e6807fcc7374b4a47347ba2..f0c6fea146b6ab254997b3573294e89c68ee5df5 100644
--- a/test/my-rdbg-tuning.ml
+++ b/test/my-rdbg-tuning.ml
@@ -3,7 +3,7 @@
 
 let _ = time_travel true;;
 
-
+(* Shortcuts for moving around *)
 let e = ref (RdbgStdLib.run());;
 let s () = e:=step !e;;
 let si i = e:=stepi !e i;;
@@ -19,15 +19,14 @@ let bt () = print_src !e;;
 let finish () = loopforever !e;;
 
 (**********************************************************************)
-(*  #require "ocamlgraph";; *)
 #mod_use "../../lib/algo/algo.ml";; 
 #mod_use "../../lib/sasacore/register.ml";;
 #mod_use "../../lib/sasacore/topology.ml";;
 #use "../rdbg-utils/dot.ml";;
 
-
-
 let p = Topology.read dotfile;;
+
+(* shortcuts for dot viewer *)
 let d () = dot p dotfile !e;;
 let ne () = neato p dotfile !e;;
 let tw () = twopi p dotfile !e;;
@@ -37,26 +36,27 @@ let sf () = sfdp p dotfile !e;;
 let pa () = patchwork p dotfile !e;;
 let os () = osage p dotfile !e;;
 
-let graph_printer =
-  ref (
+(* To be able to choose the different default dot viewer on a per  directory basis.
+   To change the graph printer: 
+   dot_view := ci;;
+*)
+let dot_view : (unit -> unit) ref =
+  ref ( (* choosing a reasonable default viewer *)
       if String.length dotfile > 4 && String.sub dotfile 0 4 = "ring" then ci else
       if Algo.is_directed () then  d else  ne)
-(** to change the graph printer
- graph_printer := ci;;
- *)
        
 
-(* Convergence is reached when data does not change *)
+(* Move forward until convergence, i.e., when no data changes *)
 let rec go () =
   let data = !e.data in
-  s(); if data = !e.data then !graph_printer () else go () ;;
+  s(); if data = !e.data then !dot_view () else go () ;;
 
-let sd () = s();!graph_printer();;
-let nd () = n();!graph_printer();;
-let bd () = b();!graph_printer();;
+let sd () = s();!dot_view();;
+let nd () = n();!dot_view();;
+let bd () = b();!dot_view();;
 
 (**********************************************************************)
-(* Computing rounds *)
+(** Computing rounds *)
 
 (* a process can be removed from the mask if one action of p is triggered
   or if no action of p is enabled *)
@@ -112,12 +112,8 @@ let (round : Event.t -> bool) =
  
 (* go to next and previous rounds  *)
 let next_round e = next_cond e round;;
-let nr () = e:=next_round !e; circo p dotfile !e;;
-let pr () = e:=goto_last_ckpt !e.nb; circo p dotfile !e;;
-
-(**********************************************************************)
-(* *)
-
+let nr () = e:=next_round !e; !dot_view ();;
+let pr () = e:=goto_last_ckpt !e.nb; !dot_view ();;
 
 (**********************************************************************)
 (* Goto to the next oracle violation *)
@@ -128,9 +124,13 @@ let goto_next_false_oracle e =
 
 let viol () = e:=goto_next_false_oracle !e
 
-(* checkpoint at rounds! *)
+(**********************************************************************)
+(* Perform the checkpointing at rounds! *)
 let _ = check_ref := round;;
 
+(**********************************************************************)
+(* Goto  to the next  event which name  contains a string  (useful for
+   navigating inside lustre or lutin programs) *)
 let next_match str e =
   next_cond e (fun e -> Str.string_match (Str.regexp_string str) e.name 0)
 let nm str = e:= next_match  str !e ;;
@@ -139,11 +139,23 @@ let prev_match str e =
   rev_cond e (fun e -> Str.string_match (Str.regexp_string str) e.name 0)
 let rm str = e:=next_match  str !e ;;
 
+(**********************************************************************)
+(* ok, let's start the debugging session! *)
+
+let pdf_viewer =
+  if Sys.command "which zathura" = 0 then "zathura" else
+  if Sys.command "which xpdf" = 0 then "xpdf" else
+  if Sys.command "which acroread" = 0 then "acroread" else
+  if Sys.command "which evince" = 0 then "evince" else
+    failwith "No pdf viewer is found"
 
 let _ =  
- !graph_printer (); 
- ignore(Sys.command (Printf.sprintf "zathura sasa-%s.pdf&" dotfile)); 
- round !e 
+  !dot_view ();
+  let cmd = Printf.sprintf "%s sasa-%s.pdf&" pdf_viewer dotfile in
+  Printf.printf "%s\n!" cmd;
+  Unix.sleep 1;
+  ignore(Sys.command cmd); 
+  round !e 
 
 let _ = print_string "
  --> type 'man' for online help
diff --git a/test/skeleton/my-rdbg-tuning.ml b/test/skeleton/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/skeleton/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/unison/Makefile b/test/unison/Makefile
index 4ebc9768c61a44c0d389bdb59aeae5cee9070d15..8c4dda0a069abbcf782c261440474129a929edf6 100644
--- a/test/unison/Makefile
+++ b/test/unison/Makefile
@@ -1,6 +1,6 @@
-# Time-stamp: <modified the 23/10/2019 (at 09:21) by Erwan Jahier>
+# Time-stamp: <modified the 23/10/2019 (at 12:18) by Erwan Jahier>
 
-test: test1 test2 lurette0 lurette1
+test: test1 test2 lurette0 lurette1 rdbg_test
 
 test1: fig41.cmxs
 	$(sasa) -l 5 fig41.dot -sd  -rif
@@ -34,10 +34,13 @@ lurette1: ring.lut ring_oracle.lus
 
 lurette: lurette0 s g
 
-rdbg: ring.ml ring.lut
+rdbg: ring.ml 
 	rdbg -o unison.rif  \
-      -env "$(sasa) ring.dot -custd -rif" \
-      -sut-nd "lutin ring.lut -n synchronous"
+      -sut "$(sasa) ring.dot -sd -rif" \
+
+rdbg_test: ring.ml
+	echo "\nnr\nsd\n" | rdbg -o unison.rif  \
+      -sut "$(sasa) ring.dot -sd -rif" \
 
 -include ../Makefile.inc
 
diff --git a/test/unison/my-rdbg-tuning.ml b/test/unison/my-rdbg-tuning.ml
deleted file mode 120000
index e83bd7c305302c3c46720aa3e77027eb0867f0c9..0000000000000000000000000000000000000000
--- a/test/unison/my-rdbg-tuning.ml
+++ /dev/null
@@ -1 +0,0 @@
-../my-rdbg-tuning.ml
\ No newline at end of file
diff --git a/test/unison/my-rdbg-tuning.ml b/test/unison/my-rdbg-tuning.ml
new file mode 100644
index 0000000000000000000000000000000000000000..9ba333d82207840466e748a80995cb21eab12ec7
--- /dev/null
+++ b/test/unison/my-rdbg-tuning.ml
@@ -0,0 +1,6 @@
+
+#use "../my-rdbg-tuning.ml";;
+
+
+
+