--- a/src/Pure/thm.ML Sat Aug 03 16:10:34 2019 +0200+++ b/src/Pure/thm.ML Sat Aug 03 16:17:16 2019 +0200@@ -382,6 +382,7 @@ fun insert_constraints thy (T, S) = let val ignored =+ ! Proofterm.proofs < 1 orelse S = [] orelse (case T of TFree (_, S') => S = S'