tuned: more robust Isabelle symbols;

--- a/src/Pure/Admin/component_jedit.scala	Sun Feb 09 12:35:29 2025 +0100
+++ b/src/Pure/Admin/component_jedit.scala	Sun Feb 09 12:47:21 2025 +0100
@@ -20,7 +20,7 @@
 
     val init: Mode =
       empty +
-        ("noWordSep" -> """_'?⇩\^<>""") +
+        ("noWordSep" -> Symbol.decode("""_'?\<^sub>\^<>""")) +
         ("unalignedOpenBrackets" -> "{[(«‹⟨⌈⌊⦇⟦⦃⦉") +
         ("unalignedCloseBrackets" -> "⦊⦄⟧⦈⌋⌉⟩›»)]}") +
         ("tabSize" -> "2") +

--- a/src/Tools/jEdit/src/pretty_text_area.scala	Sun Feb 09 12:35:29 2025 +0100
+++ b/src/Tools/jEdit/src/pretty_text_area.scala	Sun Feb 09 12:47:21 2025 +0100
@@ -361,7 +361,7 @@
   getPainter.setLineHighlightEnabled(false)
 
   getBuffer.setTokenMarker(Isabelle.mode_token_marker("isabelle-output").get)
-  getBuffer.setStringProperty("noWordSep", "_'?⇩")
+  getBuffer.setStringProperty("noWordSep", Symbol.decode("""_'?\<^sub>"""))
 
   rich_text_area.activate()
 }