[printers] declare-const must have Real type in VNN-LIB printer.

src/printers/vnnlib.ml

@@ -477,11 +477,13 @@ let print_prop_decl info fmt prop_kind pr t =
 
 let print_param_decl info fmt ls =
   match Term.Hls.find_opt info.variables ls with
+  | None -> ()
   | Some s ->
     Fmt.pf fmt ";; %s@\n" s;
-    Fmt.pf fmt "@[(declare-const %s %a)@]@\n@\n" s (print_type_value info)
-      ls.ls_value
-  | _ -> ()
+    (* FIXME: The type should not be hardcoded as 'Real', but printed as: *)
+    (* Fmt.pf fmt "@[(declare-const %s %a)@]@\n@\n" s (print_type_value info) *)
+    (*   ls.ls_value *)
+    Fmt.pf fmt "@[(declare-const %s Real)@]@\n@\n" s
 
 let print_decl info fmt d =
   match d.Decl.d_node with