Minor fix

trees/tt-0035.tree

@@ -25,7 +25,7 @@
 	\arrow[""{name=2, anchor=center, inner sep=0}, "{{{\bar{y}}}}"{pos=0.6}, dashed, from=5-1, to=1-1]
 	\arrow[""{name=3, anchor=center, inner sep=0}, "y"{description}, curve={height=24pt}, from=5-1, to=3-4]
 	\arrow["{\fF : \C(-,O)}"', Rightarrow, from=6-1, to=6-6]
-	\arrow["\in"{description}, draw=none, from=0, to=1-6]
+	\arrow["\in"{marking, allow upside down}, draw=none, from=0, to=1-6]
 	\arrow[shift left=5, curve={height=-12pt}, shorten <=17pt, shorten >=17pt, Rightarrow, from=2, to=1]
 	\arrow["\in"{marking, allow upside down}, draw=none, from=3, to=5-6]
 \end{tikzcd}