src/HOL/Tools/Quickcheck/find_unused_assms.ML

     val thy = Proof_Context.theory_of ctxt
     val ctxt' = ctxt
        |> Config.put Quickcheck.abort_potential true
        |> Config.put Quickcheck.quiet true
     val all_thms =
-      filter (fn (s, _) => length (Long_Name.explode s) = 2)  (* FIXME !? *)
-        (thms_of thy thy_name)
+      thms_of thy thy_name
+      |> filter (fn (s, _) => length (Long_Name.explode s) = 2)  (* FIXME !? *)
+      |> sort_by #1
     fun check_single conjecture =
       (case try (Quickcheck.test_terms ctxt' (true, true) []) [(conjecture, [])] of
         SOME (SOME _) => false
       | SOME NONE => true
       | NONE => false)