generate proper nicks also for instantiated induction rules

--- a/src/HOL/TPTP/mash_eval.ML	Sun Dec 16 12:07:37 2012 +0100
+++ b/src/HOL/TPTP/mash_eval.ML	Sun Dec 16 12:07:56 2012 +0100
@@ -114,10 +114,9 @@
                 ((K (nickname_of th), stature), th)
               val facts =
                 facts
-                |> map get
+                |> map (get #> nickify)
                 |> maybe_instantiate_inducts ctxt hyp_ts concl_t
                 |> take (the max_facts)
-                |> map nickify
               val ctxt = ctxt |> set_file_name heading prob_dir_name
               val res as {outcome, ...} =
                 run_prover_for_mash ctxt params prover facts goal