--- a/src/HOL/Tools/ATP/atp_systems.ML Thu Feb 01 13:55:10 2018 +0100
+++ b/src/HOL/Tools/ATP/atp_systems.ML Thu Feb 01 15:12:57 2018 +0100
@@ -514,8 +514,8 @@
(* Vampire 1.8 has TFF0 support, but the support was buggy until revision
1435 (or shortly before). *)
-fun is_vampire_at_least_1_8 () = string_ord (getenv "VAMPIRE_VERSION", "1.8") <> LESS
-fun is_vampire_beyond_1_8 () = string_ord (getenv "VAMPIRE_VERSION", "1.8") = GREATER
+fun is_vampire_at_least_1_8 () = is_greater_equal (string_ord (getenv "VAMPIRE_VERSION", "1.8"))
+fun is_vampire_beyond_1_8 () = is_greater (string_ord (getenv "VAMPIRE_VERSION", "1.8"))
val vampire_tff0 = TFF Monomorphic