diff -r 4892ceb5b29a -r 33e886e21ed4 src/HOL/Analysis/Homotopy.thy
--- a/src/HOL/Analysis/Homotopy.thy	Sun Apr 19 12:02:26 2020 +0100
+++ b/src/HOL/Analysis/Homotopy.thy	Sun Apr 19 13:01:40 2020 +0100
@@ -5,7 +5,7 @@
 section \<open>Homotopy of Maps\<close>
 
 theory Homotopy
-  imports Path_Connected Continuum_Not_Denumerable Product_Topology Sketch_and_Explore
+  imports Path_Connected Continuum_Not_Denumerable Product_Topology
 begin
 
 definition\<^marker>\<open>tag important\<close> homotopic_with