src/HOL/Mirabelle/Tools/mirabelle_sledgehammer.ML

           |> Sledgehammer_MaSh.relevant_facts ctxt params prover_name
                  (the_default default_max_facts max_facts)
                  Sledgehammer_Fact.no_fact_override hyp_ts concl_t
           |> map (apfst (apfst (fn name => name ())))
           |> tap (fn facts =>
+                     "Line " ^ str0 (Position.line_of pos) ^ ": " ^
                      (if null facts then
                         "Found no relevant facts."
                       else
                         "Including " ^ string_of_int (length facts) ^
                         " relevant fact(s):\n" ^