diff --git a/doc/Analyzing.markdown b/doc/Analyzing.markdown
index 926706f..14d4afc 100644
--- a/doc/Analyzing.markdown
+++ b/doc/Analyzing.markdown
@@ -14,7 +14,7 @@ routine.
     |   lda #4
     |   sta score
     | }
-    = main
+    = main ([])
     =   A: UpdatedWith (Immediate 4)
     =   NamedLocation (Just Byte) "score": UpdatedWith A
 
@@ -50,13 +50,13 @@ But if it does it can.
     |   jsr update_score
     |   sta border_colour
     | }
-    = main
+    = main ([])
     =   A: UpdatedWith (Immediate 4)
     =   X: PoisonedWith (Immediate 1)
     =   NamedLocation (Just Byte) "border_colour": UpdatedWith A
     =   NamedLocation (Just Byte) "score": PoisonedWith X
     = 
-    = update_score
+    = update_score ([])
     =   X: UpdatedWith (Immediate 1)
     =   NamedLocation (Just Byte) "score": UpdatedWith X
 
@@ -90,12 +90,11 @@ modifying score, as an "output" of the routine.
     |   jsr update_score
     |   ldx score
     | }
-    = main
-    =   A: UpdatedWith (Immediate 4)
-    =   X: PoisonedWith (Immediate 1)
-    =   NamedLocation (Just Byte) "border_colour": UpdatedWith A
-    =   NamedLocation (Just Byte) "score": PoisonedWith X
+    = main ([])
+    =   A: PoisonedWith (Immediate 8)
+    =   X: UpdatedWith (NamedLocation (Just Byte) "score")
+    =   NamedLocation (Just Byte) "score": UpdatedWith A
     = 
-    = update_score
-    =   X: UpdatedWith (Immediate 1)
-    =   NamedLocation (Just Byte) "score": UpdatedWith X
+    = update_score ([NamedLocation Nothing "score"])
+    =   A: UpdatedWith (Immediate 8)
+    =   NamedLocation (Just Byte) "score": UpdatedWith A
diff --git a/src/Main.hs b/src/Main.hs
index 0355cec..2c4466d 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -34,7 +34,7 @@ main = do
                 ("analyze", Right program) ->
                     case checkAndTransformProgram program of
                         Just newprog ->
-                            ppAnalysis $ analyzeProgram newprog
+                            ppAnalysis newprog (analyzeProgram newprog)
                 ("emit", Right program) ->
                     case checkAndTransformProgram program of
                         Just newprog ->
diff --git a/src/SixtyPical/Analyzer.hs b/src/SixtyPical/Analyzer.hs
index 9a6cbc1..58ecc71 100644
--- a/src/SixtyPical/Analyzer.hs
+++ b/src/SixtyPical/Analyzer.hs
@@ -81,6 +81,15 @@ mergeRoutCtxs routCtx calledRoutCtx calledRout@(Routine name outputs _) =
         poison location usage routCtxAccum =
             case usage of
                 UpdatedWith ulocation ->
-                    Map.insert location (PoisonedWith ulocation) routCtxAccum
+                    case (untypedLocation location) `elem` outputs of
+                        True ->
+                            Map.insert location usage routCtxAccum
+                        False ->
+                            Map.insert location (PoisonedWith ulocation) routCtxAccum
     in
         Map.foldrWithKey (poison) routCtx calledRoutCtx
+
+untypedLocation (NamedLocation (Just _) name) =
+    NamedLocation Nothing name
+untypedLocation x = x
+
diff --git a/src/SixtyPical/Context.hs b/src/SixtyPical/Context.hs
index c21183a..fab7078 100644
--- a/src/SixtyPical/Context.hs
+++ b/src/SixtyPical/Context.hs
@@ -26,19 +26,22 @@ type RoutineContext = Map.Map StorageLocation Usage
 
 type ProgramContext = Map.Map RoutineName RoutineContext
 
-ppAnalysis :: ProgramContext -> IO ()
-ppAnalysis progCtx =
+ppAnalysis :: Program -> ProgramContext -> IO ()
+ppAnalysis program progCtx =
     let
         li = Map.toList progCtx
     in do
-        ppRoutines li
+        ppRoutines program li
 
-ppRoutines [] = return ()
-ppRoutines ((name, routCtx):rest) = do
-    putStrLn $ name
-    ppRoutine routCtx
-    putStrLn ""
-    ppRoutines rest
+ppRoutines program [] = return ()
+ppRoutines program ((name, routCtx):rest) =
+    let
+        Just (Routine rname outputs _) = lookupRoutine program name
+    in do
+        putStrLn (rname ++ " (" ++ (show outputs) ++ ")")
+        ppRoutine routCtx
+        putStrLn ""
+        ppRoutines program rest
 
 ppRoutine routCtx =
     let