diff --git a/src/Component/Editor/Node.purs b/src/Component/Editor/Node.purs
index 6109c8f..e48e819 100644
--- a/src/Component/Editor/Node.purs
+++ b/src/Component/Editor/Node.purs
@@ -168,7 +168,7 @@ renderNode { nodeData: nodeData
             }
     _ -> mempty
 
-  maxRadius = nodeRadius + (toNumber $ List.length inputArcs - 1) * inputLayerOffset
+  maxRadius = nodeRadius + (toNumber $ List.length inputArcs - 1) * inputLayerOffset + arcWidth * 2.0
 
   valueSvg =
     maybe mempty
diff --git a/src/Component/Editor/Node/Overlays.purs b/src/Component/Editor/Node/Overlays.purs
index bd2378a..39ec336 100644
--- a/src/Component/Editor/Node/Overlays.purs
+++ b/src/Component/Editor/Node/Overlays.purs
@@ -6,7 +6,6 @@ import Prelude
 import Data.Array (mapWithIndex)
 import Data.Int (toNumber)
 import Halogen.HTML (HTML)
-import Lunarbox.Data.Editor.Constants (nodeRadius)
 import Svg.Attributes as SA
 import Svg.Elements as SE
 
@@ -20,7 +19,7 @@ overlays radius =
     <<< mapWithIndex \index elem ->
         SE.g
           [ SA.transform
-              [ SA.Translate 0.0 $ -nodeRadius + (toNumber $ (index + 1) * -20)
+              [ SA.Translate 0.0 $ -radius + (toNumber $ (index + 1) * -20)
               ]
           ]
           [ elem ]
diff --git a/src/Control/Monad/Dataflow/Interpreter/Interpret.purs b/src/Control/Monad/Dataflow/Interpreter/Interpret.purs
index 609d3d9..905999d 100644
--- a/src/Control/Monad/Dataflow/Interpreter/Interpret.purs
+++ b/src/Control/Monad/Dataflow/Interpreter/Interpret.purs
@@ -17,7 +17,6 @@ import Lunarbox.Data.Dataflow.Expression (Expression(..), Literal(..), NativeExp
 import Lunarbox.Data.Dataflow.Runtime (RuntimeValue(..))
 import Lunarbox.Data.Dataflow.Runtime.TermEnvironment as TermEnvironment
 import Lunarbox.Data.Dataflow.Runtime.ValueMap (ValueMap(..))
-import Lunarbox.Data.Lens (newtypeIso)
 
 -- Gets a value from the current environment
 getVariable :: forall l. Ord l => String -> Interpreter l RuntimeValue
@@ -27,7 +26,7 @@ getVariable name = do
 
 -- Perform an action in an environment with an extra variable
 withTerm :: forall l. Ord l => String -> RuntimeValue -> Interpreter l ~> Interpreter l
-withTerm name value = local $ over (_termEnv <<< newtypeIso) $ Map.insert (show name) value
+withTerm name value = local $ over _termEnv $ TermEnvironment.insert name value
 
 -- Interpret an expression into a runtimeValue
 interpret :: forall l. Ord l => Expression l -> Interpreter l RuntimeValue
@@ -53,14 +52,15 @@ interpret expression = do
         Nothing -> pure Null
       Let _ _ name value body -> do
         runtimeValue <- interpret value
-        local (over (_termEnv <<< newtypeIso) $ Map.insert (show name) runtimeValue) $ interpret body
+        withTerm (show name) runtimeValue $ interpret body
       FixPoint _ function -> interpret $ FunctionCall location function $ FixPoint location function
-      Native _ (NativeExpression _ call) -> pure call
-      FunctionCall _ argument function -> do
+      Native _ (NativeExpression _ inner) -> pure inner
+      FunctionCall _ function argument -> do
         runtimeArgument <- interpret argument
-        runtimeFunction <- interpret function
-        case runtimeFunction of
-          Function call -> pure $ call runtimeArgument
-          _ -> pure Null
+        runtimeFunction <-
+          interpret function
+        pure case runtimeFunction of
+          Function call -> call runtimeArgument
+          _ -> Null
   tell $ ValueMap $ Map.singleton location value
   pure value
diff --git a/src/Data/Dataflow/Expression.purs b/src/Data/Dataflow/Expression.purs
index e920601..699a87e 100644
--- a/src/Data/Dataflow/Expression.purs
+++ b/src/Data/Dataflow/Expression.purs
@@ -39,7 +39,8 @@ derive instance eqVarName :: Eq VarName
 
 derive instance ordVarName :: Ord VarName
 
-derive newtype instance showVarName :: Show VarName
+instance showVarName :: Show VarName where
+  show = unwrap
 
 derive instance newtypeVarName :: Newtype VarName _
 
diff --git a/src/Data/Dataflow/Native/ControlFlow.purs b/src/Data/Dataflow/Native/ControlFlow.purs
index daa35a6..36cc8b3 100644
--- a/src/Data/Dataflow/Native/ControlFlow.purs
+++ b/src/Data/Dataflow/Native/ControlFlow.purs
@@ -21,7 +21,9 @@ typeIf = Forall [ return ] $ TArrow typeBool $ TArrow typeReturn $ TArrow typeRe
 evalIf :: RuntimeValue -> RuntimeValue
 evalIf (Bool true) = binaryFunction const
 
-evalIf _ = binaryFunction $ flip const
+evalIf (Bool false) = binaryFunction $ flip const
+
+evalIf _ = Null
 
 if' :: NativeConfig
 if' =
diff --git a/src/Data/Dataflow/Runtime/TermEnvironment.purs b/src/Data/Dataflow/Runtime/TermEnvironment.purs
index a2bdc2a..e86d1e0 100644
--- a/src/Data/Dataflow/Runtime/TermEnvironment.purs
+++ b/src/Data/Dataflow/Runtime/TermEnvironment.purs
@@ -1,6 +1,7 @@
 module Lunarbox.Data.Dataflow.Runtime.TermEnvironment
   ( TermEnvironment(..)
   , lookup
+  , insert
   ) where
 
 import Prelude
@@ -24,3 +25,7 @@ derive newtype instance monoidTermEnvironment :: Monoid TermEnvironment
 -- Same as Map.lookup but returns Null in case the value cannot be found
 lookup :: String -> TermEnvironment -> RuntimeValue
 lookup key = fromMaybe Null <<< Map.lookup key <<< unwrap
+
+-- Wrapper around Map.insert
+insert :: String -> RuntimeValue -> TermEnvironment -> TermEnvironment
+insert key value (TermEnvironment env) = TermEnvironment $ Map.insert key value env