diff --git a/init.lua b/init.lua
index 4f6b18e..acfa3ba 100644
--- a/init.lua
+++ b/init.lua
@@ -2,7 +2,7 @@ local Tactree = {}
 local Nodes = {}
 
 local function NodeStart(node, args)
-	-- abort if started
+	-- don't start again if started
 	if node.data then return end
 
 	node.data = node.parent and node.parent.data or args
@@ -11,7 +11,7 @@ local function NodeStart(node, args)
 end
 
 local function NodeUpdate(node)
-	-- abort if not started
+	-- don't tick if not started
 	if not node.data then return end
 
 	local result = node:_tick()
@@ -91,7 +91,7 @@ function Tactree.Tree(name)
 		end
 	end
 
-	return setmetatable(node, { __index = Nodes[name] })
+	return setmetatable(node, { __index = Nodes[name], __tostring = function() return name end })
 end
 
 Tactree.Leaf 'Sequence'
@@ -142,6 +142,18 @@ Tactree.Leaf 'Selector'
 	end
 }
 
+Tactree.Leaf 'Inverter'
+{
+	start = function(node)
+		node.children[1]:start()
+	end,
+	tick = function(node)
+		local result = node.children[1]:update()
+
+		if type(result) == 'boolean' then return not result end
+	end
+}
+
 Tactree.Leaf 'RepeatUntilFail'
 {
 	start = function(node)