diff -r 9f509bc10a63 -r 508a673c87ac src/Tools/Graphview/mutator.scala
--- a/src/Tools/Graphview/mutator.scala	Tue Feb 11 23:31:12 2025 +0100
+++ b/src/Tools/Graphview/mutator.scala	Wed Feb 12 00:40:57 2025 +0100
@@ -11,7 +11,6 @@
 import isabelle._
 
 import java.awt.Color
-import scala.collection.immutable.SortedSet
 
 
 object Mutator {