diff --git a/csts.cmi b/csts.cmi
index 8af9521..81ee728 100644
Binary files a/csts.cmi and b/csts.cmi differ
diff --git a/csts.cmx b/csts.cmx
index cae2103..c8386c8 100644
Binary files a/csts.cmx and b/csts.cmx differ
diff --git a/csts.ml b/csts.ml
index 7a53619..2e15574 100644
--- a/csts.ml
+++ b/csts.ml
@@ -28,6 +28,10 @@ let sleep_d = 0.01 ;;
 let difficulty = ref 1 ;;
 let calc_length = ref 3 ;;
 let time_to_ans = ref 10 ;;
+let n_inf = ref 1 ;;
+let n_sup = ref 10 ;;
+
+let time_to_ans_f = ref 10.0 ;;
 
 let score = ref 0
 and combo = ref 0
diff --git a/csts.o b/csts.o
index 1eafff9..4a2e8a0 100644
Binary files a/csts.o and b/csts.o differ
diff --git a/drawing.cmi b/drawing.cmi
index bb2d2ae..686d574 100644
Binary files a/drawing.cmi and b/drawing.cmi differ
diff --git a/drawing.cmx b/drawing.cmx
index 9a0c149..27b633c 100644
Binary files a/drawing.cmx and b/drawing.cmx differ
diff --git a/drawing.ml b/drawing.ml
index cdf2851..5b90251 100644
--- a/drawing.ml
+++ b/drawing.ml
@@ -76,6 +76,48 @@ let draw_integer_alignedleft ?retval:(rv=fodder) x0 y n0 len =
     done ;
     rv := (x0 + (size+1)*(len*11/7)) ;;
 
+let draw_integer_alignedright ?retval:(rv=fodder) x0 y n0 len =
+  (* 7-seg display 2 *)
+  set_line_width (max 1 (len/4));
+  let n = ref n0 in
+  let size = Math.ln_b 10 n0 in
+
+  let cur_x = ref (x0 - len*11/7) in
+
+  if !n < 0 then begin
+      n := !n * (-1);
+      draw_poly_line [|(x0, y); (x0-(size+1)*len, y)|];
+      cur_x := !cur_x + (len*11/7)
+  end;
+
+  for i = 0 to size do
+      let x = !cur_x in
+      if Array.mem (!n mod 10) [|0; 4; 5; 6; 7; 8; 9|] then
+          draw_poly_line [|(x + !(Csts.camx), y+len + !(Csts.camy)); (x + !(Csts.camx), y + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|0; 2; 3; 5; 6; 7; 8; 9|] then
+          draw_poly_line [|(x + !(Csts.camx), y+len + !(Csts.camy)); (x+len + !(Csts.camx), y+len + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|0; 1; 2; 3; 4; 7; 8; 9|] then
+          draw_poly_line [|(x+len + !(Csts.camx), y+len + !(Csts.camy)); (x+len + !(Csts.camx), y + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|2; 3; 4; 5; 6; 8; 9|] then
+          draw_poly_line [|(x + !(Csts.camx), y + !(Csts.camy)); (x+len + !(Csts.camx), y + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|0; 1; 3; 4; 5; 6; 7; 8; 9|] then
+          draw_poly_line [|(x+len + !(Csts.camx), y-len + !(Csts.camy)); (x+len + !(Csts.camx), y + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|0; 2; 3; 5; 6; 8; 9|] then
+          draw_poly_line [|(x + !(Csts.camx), y-len + !(Csts.camy)); (x+len + !(Csts.camx), y-len + !(Csts.camy))|];
+
+      if Array.mem (!n mod 10) [|0; 2; 6; 8|] then
+          draw_poly_line [|(x + !(Csts.camx), y-len + !(Csts.camy)); (x + !(Csts.camx), y + !(Csts.camy))|];
+
+      n := !n/10;
+      cur_x := !cur_x - (len*11/7);
+    done ;
+    rv := (x0 + (len*11/7)) ;;
+
 let decode_letter x y len arr =
   set_line_width 3;
   if arr.(0) = 1 then
diff --git a/drawing.o b/drawing.o
index 5e5219c..d973d3b 100644
Binary files a/drawing.o and b/drawing.o differ
diff --git a/dynamic.cmx b/dynamic.cmx
index 70495ec..9e5b0d8 100644
Binary files a/dynamic.cmx and b/dynamic.cmx differ
diff --git a/dynamic.o b/dynamic.o
index 7a3f91d..0bf5156 100644
Binary files a/dynamic.o and b/dynamic.o differ
diff --git a/maeth.cmi b/maeth.cmi
index a4c9a50..36384f4 100644
Binary files a/maeth.cmi and b/maeth.cmi differ
diff --git a/maeth.cmx b/maeth.cmx
index 1476a5f..7bcbcaa 100644
Binary files a/maeth.cmx and b/maeth.cmx differ
diff --git a/maeth.ml b/maeth.ml
index 7d159c5..b3d511f 100644
--- a/maeth.ml
+++ b/maeth.ml
@@ -117,4 +117,19 @@ let print_calc (f : operation) (x0 : int) (y0 : int) (size : int) =
       aux g ;
       if require_bracket g then draw_bracket_close !x y0 size ~retval:x ;
   in
-  aux f ;;
\ No newline at end of file
+  aux f ;;
+
+let maeth_main () =
+  let start = Unix.gettimeofday () in
+  let found = ref false in
+  while not !found && (Unix.gettimeofday() -. start <= !Csts.time_to_ans_f) do
+    ()
+  done ;
+  if !found then begin
+    incr Csts.combo ;
+    true
+  end
+  else begin
+    Csts.combo := 0 ;
+    false
+  end ;;
\ No newline at end of file
diff --git a/maeth.o b/maeth.o
index 2b2da2f..fc5c70c 100644
Binary files a/maeth.o and b/maeth.o differ
diff --git a/main.cmi b/main.cmi
index 7eb4cdc..744e235 100644
Binary files a/main.cmi and b/main.cmi differ
diff --git a/main.cmx b/main.cmx
index dc512ff..1cc2ecd 100644
Binary files a/main.cmx and b/main.cmx differ
diff --git a/main.ml b/main.ml
index 9d1006f..87a7d00 100644
--- a/main.ml
+++ b/main.ml
@@ -16,6 +16,7 @@ let mainloop () =
     ()
   with
     | Menus.MenuStart ->
+      Csts.time_to_ans_f := float_of_int (!Csts.time_to_ans) ;
       clear_graph () ;
       Maeth.print_calc (Maeth.generate_random_calc 8 1 20) (10) (Csts.__height__/2) 20 ;
       while true do
diff --git a/main.o b/main.o
index 0d688fc..46ad304 100644
Binary files a/main.o and b/main.o differ
diff --git a/math b/math
index b2ac13c..2e9b48d 100755
Binary files a/math and b/math differ
diff --git a/math.cmx b/math.cmx
index 210928b..739422b 100644
Binary files a/math.cmx and b/math.cmx differ
diff --git a/math.o b/math.o
index b25fa5e..8fa32ed 100644
Binary files a/math.o and b/math.o differ
diff --git a/menus.cmi b/menus.cmi
index 6f9a376..5218deb 100644
Binary files a/menus.cmi and b/menus.cmi differ
diff --git a/menus.cmx b/menus.cmx
index 22d9be9..adbefec 100644
Binary files a/menus.cmx and b/menus.cmx differ
diff --git a/menus.ml b/menus.ml
index 0acd1c2..822483d 100644
--- a/menus.ml
+++ b/menus.ml
@@ -10,6 +10,8 @@ type 'a value_changer = {
   min : 'a ;
   max : 'a ;
   pad : 'a ;
+  min_update : ('a ref) list ; (* after this value changes, these values will be set to min(their_value, this_value-1) *)
+  max_update : ('a ref) list ; (* after this value changes, these values will be set to max(their_value, this_value+1) *)
 } ;;
 
 type action = Nothing | Tweak of int value_changer | Warp of int
@@ -120,11 +122,13 @@ let build_interface (title : string) (red : int) (green : int) (blue : int) (but
   Dynamic.dyn_add arr_interfaces res ;
   incr current_interface_index ;;
 
-let build_tweak (ptr : int ref) (m : int) (mx : int) (st : int) = {
+let build_tweak (ptr : int ref) (m : int) (mx : int) (st : int) (mi : (int ref) list) (sp : (int ref) list) = {
     ptr = ptr ;
     min = m;
     max = mx ;
     pad = st ;
+    min_update = mi ;
+    max_update = sp ;
   } ;;
 
 (* --------------------------------------------------------------------------------------------------------------------------------------------- *)
@@ -162,7 +166,11 @@ let print_button (b : button) =
   fill_rect b.pos.x b.pos.y b.pos.w b.pos.h ;
   draw_closest b.red b.green b.blue ;
   set_line_width 2 ;
-  Drawing.draw_string (b.pos.x+3) (b.pos.y + b.pos.h/2) b.text (min (3*b.pos.h/4-2) ((7*(b.pos.w*3/4-4)/(max 1 (String.length b.text)))/10)) ;;
+  Drawing.draw_string (b.pos.x+3) (b.pos.y + b.pos.h/2) b.text (min (3*b.pos.h/4-2) ((7*((b.pos.w*3)/4-50)/(max 1 (String.length b.text)))/10)) ;
+  match b.actn with
+    | Tweak v ->
+      Drawing.draw_integer_alignedright (b.pos.x + b.pos.w) (b.pos.y + b.pos.h/2) !(v.ptr) 15
+    | _ -> () ;;
 
 let print_interface (it : interface) =
   List.iter print_button it.bts ;
@@ -176,7 +184,7 @@ let print_current_interface () =
   Drawing.draw_string 20 (Csts.__height__ - 40) interf.title 30 ;;
 
 (* --------------------------------------------------------------------------------------------------------------------------------------------- *)
-(* actions *)
+(* actions 1/2 *)
 
 let get1char () =
   if key_pressed () then
@@ -184,13 +192,116 @@ let get1char () =
   else
     '@' ;;
 
+let change_other (reference : int) (mins : (int ref) list) (maxs : (int ref) list) =
+  let rec aux = function
+    | ([], []) -> 
+      ()
+    | (hmin::tmin, []) ->
+      hmin := min (!hmin) (reference -1) ;
+      aux (tmin, [])
+    | ([], hmax::tmax) ->
+      hmax := max (!hmax) (reference +1) ;
+      aux ([], tmax)
+    | (hmin::tmin, hmax::tmax) ->
+      hmin := min (!hmin) (reference -1) ;
+      hmax := max (!hmax) (reference +1) ;
+      aux (tmin, tmax)
+  in aux (mins, maxs) ;;
+
+let offset_pm = 40 ;;
+let size_pm = (Csts.__width__ - 2*offset_pm) /11 ;;
+
+let draw_rect_pm (x : int) (y : int) (w: int) (h : int) (red : int) (green : int) (blue : int) =
+  let (mx, my) = mouse_pos () in
+  if is_within {x = x; y = y; w = w; h = h} mx my then begin
+    set_color (rgb 0 255 0) ;
+    fill_rect x y w h ;
+    set_color (rgb red green blue) ;
+    fill_rect (x+6) (y+6) (w-12) (h-12) 
+  end
+  else begin
+    set_color (rgb red green blue) ;
+    fill_rect x y w h 
+  end ;;
+
+let draw_incrdecr () =
+  draw_rect_pm (offset_pm)                     (offset_pm) size_pm size_pm 255 0 0;
+  draw_rect_pm (Csts.__width__/11 + offset_pm) (offset_pm) size_pm size_pm 255 0 0;
+  draw_rect_pm (2*Csts.__width__/11 + offset_pm) (offset_pm) size_pm size_pm 255 0 0;
+  draw_rect_pm (3*Csts.__width__/11 + offset_pm) (offset_pm) size_pm size_pm 255 0 0;
+  draw_rect_pm (4*Csts.__width__/11 + offset_pm) (offset_pm) size_pm size_pm 255 0 0;
+  draw_rect_pm (10*Csts.__width__/11 - offset_pm) (offset_pm) size_pm size_pm 0 0 255;
+  draw_rect_pm (9*Csts.__width__/11 - offset_pm) (offset_pm) size_pm size_pm 0 0 255;
+  draw_rect_pm (8*Csts.__width__/11 - offset_pm) (offset_pm) size_pm size_pm 0 0 255;
+  draw_rect_pm (7*Csts.__width__/11 - offset_pm) (offset_pm) size_pm size_pm 0 0 255;
+  draw_rect_pm (6*Csts.__width__/11 - offset_pm) (offset_pm) size_pm size_pm 0 0 255;;
+
+let draw_digits_incrdecr () =
+  set_color white ;
+  Drawing.draw_string_centered (offset_pm + size_pm/2) (offset_pm + size_pm/2) "min" (size_pm/6) ;
+  Drawing.draw_integer (offset_pm + Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 1 (size_pm/3) ;
+  Drawing.draw_integer (offset_pm + 2*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 10 (size_pm/3) ;
+  Drawing.draw_integer (offset_pm + 3*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 100 (size_pm/3) ;
+  Drawing.draw_integer (offset_pm + 4*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 500 (size_pm/3) ;
+  
+  Drawing.draw_string_centered (-offset_pm + 10*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) "max" (size_pm/6) ;
+  Drawing.draw_integer (-offset_pm + 9*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 1 (size_pm/3) ;
+  Drawing.draw_integer (-offset_pm + 8*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 10 (size_pm/3) ;
+  Drawing.draw_integer (-offset_pm + 7*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 100 (size_pm/3) ;
+  Drawing.draw_integer (-offset_pm + 6*Csts.__width__/11 + size_pm/2) (offset_pm + size_pm/2) 500 (size_pm/3) ;;
+
+(* --------------------------------------------------------------------------------------------------------------------------------------------- *)
+(* actions 2/2 *)
+
+let stall_pm = ref false ;;
+let use_incrdecr (val_ptr : int value_changer) =
+  if button_down () then begin
+    if !stall_pm then 
+      () 
+    else begin
+      stall_pm := true ;
+      let (mox, moy) = mouse_pos () in
+      if moy >= offset_pm && moy <= offset_pm + size_pm then begin
+        match mox with
+          | x when x >= offset_pm && x <= offset_pm + size_pm -> 
+            val_ptr.ptr := val_ptr.min
+          | x when x >= offset_pm + Csts.__width__/11 && x <= offset_pm + Csts.__width__/11 + size_pm -> 
+            val_ptr.ptr := max val_ptr.min (!(val_ptr.ptr) - 1)
+          | x when x >= offset_pm + 2*Csts.__width__/11 && x <= offset_pm + 2*Csts.__width__/11 + size_pm -> 
+            val_ptr.ptr := max val_ptr.min (!(val_ptr.ptr) - 10)
+          | x when x >= offset_pm + 3*Csts.__width__/11 && x <= offset_pm + 3*Csts.__width__/11 + size_pm -> 
+            val_ptr.ptr := max val_ptr.min (!(val_ptr.ptr) - 100)
+          | x when x >= offset_pm + 4*Csts.__width__/11 && x <= offset_pm + 4*Csts.__width__/11 + size_pm -> 
+            val_ptr.ptr := max val_ptr.min (!(val_ptr.ptr) - 500)
+
+          | x when x >= 6*Csts.__width__/11 - offset_pm && x <= 6*Csts.__width__/11 - offset_pm + size_pm -> 
+            val_ptr.ptr := min val_ptr.max (!(val_ptr.ptr) + 500)
+          | x when x >= 7*Csts.__width__/11 - offset_pm && x <= 7*Csts.__width__/11 - offset_pm + size_pm -> 
+            val_ptr.ptr := min val_ptr.max (!(val_ptr.ptr) + 100)
+          | x when x >= 8*Csts.__width__/11 - offset_pm && x <= 8*Csts.__width__/11 - offset_pm + size_pm -> 
+            val_ptr.ptr := min val_ptr.max (!(val_ptr.ptr) + 10)
+          | x when x >= 9*Csts.__width__/11 - offset_pm && x <= 9*Csts.__width__/11 - offset_pm + size_pm -> 
+            val_ptr.ptr := min val_ptr.max (!(val_ptr.ptr) + 1)
+          | x when x >= 10*Csts.__width__/11 - offset_pm && x <= 10*Csts.__width__/11 - offset_pm + size_pm -> 
+            val_ptr.ptr := val_ptr.max
+          | _ -> ()
+      end
+    end
+  end 
+  else
+    stall_pm := false ;;
+
 let move_interface (b : button) = match b.actn with
   | Nothing -> ()
   | Tweak val_ptr -> begin
     let halted = ref false in
+    set_color black ;
+    Drawing.draw_string_centered (Csts.__width__/2) (Csts.__height__ - 50) "press space to confirm" 15 ;
     set_line_width 3 ;
     while not !halted do
       auto_synchronize false ;
+      draw_incrdecr () ;
+      draw_digits_incrdecr () ;
       set_color black ;
       fill_rect (3*Csts.__width__/10) (3*Csts.__height__/10) (2*Csts.__width__/5) (2*Csts.__height__/5) ;
       set_color white ;
@@ -201,13 +312,15 @@ let move_interface (b : button) = match b.actn with
       Drawing.draw_string (7*Csts.__width__/10-5-3*20*10/7) (11*Csts.__height__/20) "Max" 20 ;
       Drawing.draw_integer_alignedleft (7*Csts.__width__/10-5-3*20*10/7) (Csts.__height__/2) val_ptr.max 18 ;
       auto_synchronize true ;
+      use_incrdecr val_ptr ;
       Unix.sleepf Csts.sleep_d ;
       match get1char () with
         | '+' -> val_ptr.ptr := min val_ptr.max (!(val_ptr.ptr) + val_ptr.pad)
         | '-' -> val_ptr.ptr := max val_ptr.min (!(val_ptr.ptr) - val_ptr.pad)
         | '\n' | ' ' -> halted := true
         | _ -> ()
-    done
+    done ;
+    change_other !(val_ptr.ptr) val_ptr.min_update val_ptr.max_update
   end
   | Warp ne ->
     if ne = -1 then 
@@ -255,10 +368,13 @@ build_empty_interface "Options  " 32 32 32 ;;
 build_button "Start"      {x = Csts.__width__/2 - 150; y = 270; w = 300; h = 100} 32 255 32 (Warp (-2)) ;;
 build_button "Options"    {x = Csts.__width__/2 - 150; y = 160; w = 300; h = 100} 255 32 255 (Warp 1) ;;
 build_button "Exit"       {x = Csts.__width__/2 - 150; y = 50; w = 300; h = 100} 1 1 1 (Warp (-1)) ;;
-build_button "Length"     {x = Csts.__width__/2 - 150; y = 380; w = 300; h = 100}  255 32 32 (Tweak (build_tweak Csts.calc_length 2 20 1)) ;;
-build_button "Time"       {x = Csts.__width__/2 - 150; y = 270; w = 300; h = 100} 32 255 32 (Tweak (build_tweak Csts.time_to_ans 3 30 1)) ;;
-build_button "Difficulty" {x = Csts.__width__/2 - 150; y = 160; w = 300; h = 100} 32 32 255 (Tweak (build_tweak Csts.difficulty 1 10 1)) ;;
-build_button "Back"       {x = Csts.__width__/2 - 150; y = 50; w = 300; h = 100} 32 32 32 (Warp 0) ;;
+
+build_button "Minimum"    {x = Csts.__width__/2 - 200; y = 600; w = 400; h = 100}  255 128 32 (Tweak (build_tweak Csts.n_inf 1 1000 1 [] [Csts.n_sup])) ;;
+build_button "Maximum"    {x = Csts.__width__/2 - 200; y = 490; w = 400; h = 100}  128 255 32 (Tweak (build_tweak Csts.n_sup 1 1000 1 [Csts.n_inf] [])) ;;
+build_button "Length"     {x = Csts.__width__/2 - 200; y = 380; w = 400; h = 100}  255 32 32 (Tweak (build_tweak Csts.calc_length 2 20 1 [] [])) ;;
+build_button "Time"       {x = Csts.__width__/2 - 200; y = 270; w = 400; h = 100} 32 255 32 (Tweak (build_tweak Csts.time_to_ans 3 30 1 [] [])) ;;
+build_button "Difficulty" {x = Csts.__width__/2 - 200; y = 160; w = 400; h = 100} 32 32 255 (Tweak (build_tweak Csts.difficulty 1 10 1 [] [])) ;;
+build_button "Back"       {x = Csts.__width__/2 - 200; y = 50; w = 400; h = 100} 32 32 32 (Warp 0) ;;
 
 (*Printf.printf "(B : %d ; I : %d)\n" arr_buttons.len arr_interfaces.len ;;*)
 add_button_to_interface 0 0 ;
@@ -267,4 +383,6 @@ add_button_to_interface 0 2 ;
 add_button_to_interface 1 3 ;
 add_button_to_interface 1 4 ;
 add_button_to_interface 1 5 ;
-add_button_to_interface 1 6 ;
\ No newline at end of file
+add_button_to_interface 1 6 ;
+add_button_to_interface 1 7 ;
+add_button_to_interface 1 8 ;
\ No newline at end of file
diff --git a/menus.o b/menus.o
index 9943652..1973d72 100644
Binary files a/menus.o and b/menus.o differ