let rec file_concat l =
match l with
+--- why3-for-spark-gpl-2017-src/src/coq-tactic/why3tac.ml4.old 2017-10-26 22:25:55.289094778 +0200
++++ why3-for-spark-gpl-2017-src/src/coq-tactic/why3tac.ml4 2017-10-26 22:26:10.719807270 +0200
+@@ -1352,7 +1352,7 @@
+ let limit =
+ { Call_provers.empty_limit with Call_provers.limit_time = timelimit } in
+ let call = Driver.prove_task ~command ~limit drv !task in
+- wait_on_call call
++ wait_on_call (ServerCall call)
+ with
+ | NotFO ->
+ if debug then Printexc.print_backtrace stderr; flush stderr;
+@@ -1399,14 +1399,8 @@
+ | StepLimitExceeded -> error "Step Limit Exceeded"
+ | HighFailure -> error ("Prover failure\n" ^ res.pr_output ^ "\n")
+
+-IFDEF COQ84 THEN
+-
+-ELSE
+-
+ let why3tac ?timelimit s = Proofview.V82.tactic (why3tac ?timelimit s)
+
+-END
+-
+ end
+
+ TACTIC EXTEND Why3