--- a/src/HOL/Analysis/Abstract_Topology.thy Sun Apr 07 21:05:22 2019 +0200
+++ b/src/HOL/Analysis/Abstract_Topology.thy Mon Apr 08 15:26:54 2019 +0100
@@ -2728,7 +2728,7 @@
"X homeomorphic_space Y \<longleftrightarrow> Y homeomorphic_space X"
unfolding homeomorphic_space_def by (metis homeomorphic_maps_sym)
-lemma homeomorphic_space_trans:
+lemma homeomorphic_space_trans [trans]:
"\<lbrakk>X1 homeomorphic_space X2; X2 homeomorphic_space X3\<rbrakk> \<Longrightarrow> X1 homeomorphic_space X3"
unfolding homeomorphic_space_def by (metis homeomorphic_maps_compose)