Fix command line argument check in debugger

Also shows the correct binary name in the usage output.

src/debugger/debugger.ml

@@ -20,11 +20,11 @@ let nomTable name =
 
 let _ = Gc.set { (Gc.get()) with Gc.minor_heap_size = 4194304; major_heap_increment = 67108864; space_overhead = 120 }
 
-let printUsage () =
-  print_endline "Usage: \"debugger <functor> <formula>\" where";
+let printUsage name =
+  print_endline ("Usage: \"" ^ name ^ " <functor> <formula>\" where");
   print_endline "";
   print_endline "Examples:";
-  print_endline "./debugger.native  '(Const a b) * (Const c) * (Const d)'  '( [pi1] =a <=> [pi2][pi1] =c) & ([pi1] =b <=> [pi2][pi2] =d)'";
+  print_endline (name ^ "  '(Const a b) * (Const c) * (Const d)'  '( [pi1] =a <=> [pi2][pi1] =c) & ([pi1] =b <=> [pi2][pi2] =d)'");
   exit 1
 
 let printResult () =
@@ -90,7 +90,7 @@ let showNode = function
     | [] -> print_endline "Error: number required!"
 
 let _ =
-  if Array.length Sys.argv < 2 then printUsage()
+  if Array.length Sys.argv < 3 then printUsage Sys.argv.(0)
   else
     let formula = Sys.argv.(2) in
     let sorts = (FE.sortTableFromString Sys.argv.(1)) in