+(/ ⊄ # similar to (_
+)/ ⊅ # similar to )_
+(+ ∉ # (- with stroke
++) ∌ # -) with stroke
+0X ⊗ # *X like 0.
++0 ⊕ # 0+ already in use
+0/ ⊘
+0- ⊖
+0* ⊛ #XXX alternatively ⍟
+0: ⨸
+0% ⦼ # no circled percent, but close
+0< ⧀
+0= ⊜
+0> ⧁
+0! ⦶ # no circled exclamation mark