diff -r 4f2bd13edce3 -r dbaed92fd8af src/Pure/Proof/proof_rewrite_rules.ML
--- a/src/Pure/Proof/proof_rewrite_rules.ML	Sat Sep 04 22:05:35 2021 +0200
+++ b/src/Pure/Proof/proof_rewrite_rules.ML	Sat Sep 04 22:17:15 2021 +0200
@@ -249,7 +249,7 @@
           if member (op =) defs s then
             let
               val vs = vars_of prop;
-              val tvars = rev (Term.add_tvars prop []);
+              val tvars = build_rev (Term.add_tvars prop);
               val (_, rhs) = Logic.dest_equals (Logic.strip_imp_concl prop);
               val rhs' = Term.betapplys (subst_TVars (map fst tvars ~~ Ts)
                 (fold_rev (fn x => fn b => Abs ("", dummyT, abstract_over (x, b))) vs rhs),