src/HOL/Mutabelle/mutabelle_extra.ML

 
 fun invoke_try thy t =
   let
     val state = Proof.theorem NONE (K I) (map (single o rpair []) [t]) (ProofContext.init_global thy)
   in
-    case Try.invoke_try (SOME (seconds 5.0)) state of
+    case Try.invoke_try (SOME (seconds 5.0)) ([], [], []) state of
       true => (Solved, ([], NONE))
     | false => (Unsolved, ([], NONE))
   end
 
 val try_mtd = ("try", invoke_try)